I decided to post this in the forum instead of private messaging it to you, because I'm greedily baiting for commendations.
DISCLAIMER: I'm just one guy, and my opinion isn't going to be the same as everyone's. Some phrasings I like or dislike might be caused by personal bias, so don't take my opinions on your wording as the "right" way.
(My comments are in italics)
“WATCH OUT!” I bolt upright in a cold sweat. You need a second space after the dialogue.
“That dream again?” Not a comment on writing style, but I'm curious what the dream actually was. Is it important to the plot at all? You could get some foreshadowing in here if you do it right.
I look to my right, the room is still dark, but I still see Issac’s sapphire blue eyes sitting on the old chair against the wall. 1) This sentence is a bit of a run-on and has some grammar issues. I recommend instead splitting it into two sentences, with "I look to my right" being the first sentence. This speeds up the pace and is easier to read. 2) Are Isaac's sapphire blue eyes the things sitting on the old chair? Either just say Isaac himself is sitting in the old chair, or say you can see his eyes shinning in the gloom or something, it's a bit distracting to say his eyes are sitting in a chair. 3) I still don't like the sapphire blue eyes thing, but I think that's my problem, not yours. “Yeah,” looking at the clock I notice the time, “It’s still only 4:00.” There's some grammar issues with this sentence. Both commas should be a periods, and you have a double space in the middle. I'm going to stop pointing out your dialogue mistakes for the rest of this, though, as once you get the hang of it, you should be able to fix them pretty easily yourself. I groan as I haul myself out of bed, and go to the closet. No problems here. To make the sentence structure a little tighter, maybe have "I groan" be the dialogue tag of the previous sentence, and make the rest its own sentence. I sigh “I might as well get ready because it’s not like I will be able to fall back asleep,” looking over my shoulder at Issac and notice that his wings are out again as they give off a light that is as pure as the color of his wings, “your wings are showing again.” 1) This is a run-on sentence again. Break it up into 2 or 3 sentences to make it easier to read and quicken the pace. 2) "They give off a light that is as pure as the color of his wings". What does this mean? Your wording is very vague here. I recommend just saying that the wings give off light.
“I thought you could use some light,” Issac claimed, grinning cheekily. The use of the adverb "cheekily" is an example of telling not showing. It's clear from the words "claimed" and "grinning" that he's saying this cheekily, so cutting that word would help reader immersion. I might recommend cutting the word "claimed" too, and just making it "Isaac grinned. "I thought you could use some light.""
“Uh-huh, okay, you know as well as I do that the only clothes in here are my station uniforms,” I look back at the closet and pick up a uniform (they all look the same),Slight run-on sentence here. I recommend splitting this up. Also, the addition in parenthesis is unnecessary. “All I need to do is pick a hanger. I’m gonna go take a shower… Do you mind if I turn on some music?” I turn back around to walk to the bathroom across the room. I know this pattern so well that I can do this in the dark. There's nothing wrong with this part. It doesn't seem too relevant, though. Why is it important that the narrator can do this walk in the dark? Why is it important that they're turning on some music?
“You know, you should tell someone about your nightmares,” Issac states, giving me a look that tells me he knows what I’m thinking, and he doesn’t agree. Again, telling not showing. You can convey Isaac's opinion through physical descriptions. I recommend something like "Isaac gives me a long look. "You know, you should..." etc."
“And you should know that if I do that, I could very well be fired in the process, or at least be forced to retire early,” I reply after turning around and giving him a look that says there’s no way in hell I’m telling someone. Again, you're telling not showing, and this is a bit of a run-on sentence. Perhaps something like "I match Isaac's gaze. "And you should know..." etc." This part is a bit wordy too, you can probably cut it down. It’s still dark, but that doesn’t stop me from seeing Issac as the glow given off by the wings lights up his figure. This sentence doesn't add anything.
Issac looks at me with a frown, “Why won’t you tell anyone? It’s not going to get better if you don’t tell someone.” "It's not going to get better on it's own" is tighter phrasing.
“I’m telling you”
“Yeah, but I’m in your head, you made me,” Issac replies, waiting for my response. 1) Saying that Isaac is waiting for the narrator's response doesn't make sense unless the narrator takes a long time to answer. If that's what you're trying to convey, maybe have the next sentence be ""Okay so what?" I say at last." 2) Overall, I'm not sure I like the way this is phrased. Something like ""I meant someone real," says Isaac, rolling his eyes." might be smoother. Your call.
“Okay, so what? I’ll live; I’ve lasted this long without telling anyone,” I reply, starting to get agitated. You can show the narrator is agitated without saying it by describing his actions. Maybe they start pacing, or you can tag the dialogue as "I snap" rather than "I reply".
“Go take a shower, and cool down before you blow up at me Teske (Is this supposed to be the narrator's name?),” Issac warns, noticing my change in temperament.
“Yeah, yeah,” I grumble, I turn around and stalk into the bathroom, slamming the door behind me. Good example of showing instead of telling.
The rest of the time till I got to work ("the morning" might be better than "the time till I got to work" (assuming it is morning)), was in silence. Issac didn’t bother to get in the car when I left the apartment to go to work, he knew better than to keep bothering me. I also knew though that Issac would be at the station when I arrived. Phrasing here is a bit clunky. I suggest "But I knew he would be at the station when I arrived."
Stepping out of my car, I see Issac. I’m early again, so everyone else from my shift isn’t here yet, and it looks like the current shift is out on calls (the apparatus bay was empty) The bit in parenthesis isn't needed. Also, you can probably communicate the same information in less words. I go to the trunk of my car and pull out my bag that contains bed sheets. Why do they have a bag with bed sheets? Afterwards, I walk into the station, I look around and I see that the front is a mess, and I mean there are ceiling tiles that are either torn down or hanging off the ceiling. The floor is also littered with broken chairs, desks, and other office materials. This should be a dramatic sequence. The best way to show that is shorter sentences, shorter words, and increased pacing, with only limited internal descriptions. The narrator's description here is too casual to convey the surprise. I suggest breaking this up into 4-5 short sentences, with each one focusing on a different detail.
Still holding my bag I walk towards the sleeping quarters while avoiding the debris on the floor, “Hello, (Should be a question mark)” I’m concerned because the front is always tidy. I move into the kitchen and it’s also a complete mess as well with the pots and pans scattered everywhere, broken dishes on the floor, it looks like someone took all the food from fridges, ate the food, then threw up everywhere. By this point, I’m concerned that I might be in danger as I don’t know how or why everything is a mess. Same as above. Shorter sentences and less musing to increase the tension.
I walk into the apparatus bay and it’s empty of the apparatus as I’d seen before, but it is clean; this room is still in good condition even though all the other rooms were a complete mess. Suddenly, (Interestingly, using the word suddenly actually decreases tension. The best way to show that an action is sudden and unexpected is to have it start a new paragraph. If it's really sudden, you can have the previous paragraph cut off with a dash.) the lights go out, when they come back on, what I see makes my blood turn cold, the whole room is covered in gore, the bodies of my brothers (not brothers by blood) (This addition breaks the pace) are strewn everywhere. Run-on sentence, break it up. Some of their bodies are missing arms and legs, but all the bodies have had their heads decapitated. I turn around because I’m about ready to crap my pants, and I feel like someone’s behind me. Why does the narrator feel like someone's behind them? Better to use an event, like hearing someone take a step or something. When I turn around, that’s when I see the heads. The heads of my fellow brothers staring at me with looks of anger, disappointment, and disbelief.
“This is what happens when you don’t tell someone about your issues.” I look away from the heads to see Issac. His wings are showing, but now they are black, almost like obsidian, and his once sapphire eyes hold a darkness that I cannot understand. "A darkness I cannot understand" is telling rather than showing.
“What do you mean?” I ask, “What did you do?!” I scream at Issac;(I recommend splitting the sentence here) there is no more empathy in his eyes. You can get rid of "I ask", you don't need more than one dialogue tag here.
“This is what you deserve,” Issac states as he pulls out a gun.
do this,” Is this a typo?
“No, no, no,” I start to back away, but I trip over one of the bodies, “please don’t," I beg.
“It must be done,” Issac walks up to me, leans over, and fires. Not a writing style comment, but what exactly has convinced Isaac that this is a good idea? Does he think this is really the best way to help the narrator, or is he just nuts? This may not be important to your story.
I wake up in a hospital bed, when I try to sit up, I find that I have been handcuffed to the bed. Split into multiple sentences. I look up and I see an officer standing by the door. “What happened?” I ask the officer. The officer looks at me a little taken aback and answers, “You don’t remember?” I'm not sure what police procedure would be in this case. If you intend to seriously revise this, you should do some research.
“No, should I?” I inquire, confused. If they're inquiring, they must be confused. You don't need to clarify that.
“You killed everyone at the fire station then you shot yourself,” the officer replies.
“What do you mean?”
“I mean that you killed everyone at the station you worked at, decapitated everyone and put their heads on one side facing you, and you shot yourself,” The police officer is very matter of fact here, but again, I'm not sure what procedure is in these cases.
“So it wasn’t a dream?” I say in horror and disbelief. Try showing and not telling, etc. etc.
“No, it was very much real,” the officer confirms, looking haunted as though he was reliving the scene. Try showing and not telling, etc. etc.
1) I haven't corrected all your grammar/dialogue mistakes, so go read up on those rules and then go over this again.
2) Because the issues with this are largely based on phrasing and a couple bad habits, your writing strikes me as the kind that will improve quickly with lots of practice and some feedback. Your general problem seems to be that you say more than you need to, slowing down the pace of your writing. Once you kick that habit, your writing will probably improve considerably.
3) Directly stating character thoughts can be a stylistic choice. If you really really like that aspect of your writing, you can look into a style of writing that allows for it. It's much harder to do well, however.
4) To end on a compliment, I'd like to say again that your sticking tightly to the concept you had has payed off, and made the story much more readable and enjoyable than many other similar stories that try to become too complex.