Honestly, I do get that feeling. So you don't have to feel like it's just you feeling it. Lots of people get insecure. But, you know what? That's okay that you feel that way. That energy is going to be there no matter what, you can't fight it. What you can do is figure out if that energy is going to be a negative or a positive. I'm extremely self-critical, but I use that to figure out how I can do better. Rather than a weight to drag me down, I use it as a motive for improving.
Yes, other people are going to write better; others will write worse, too. You know who will write better than you? You, with more experience. The only way to get there is to do that writing, put your work out there, and learn from your experiences. It's okay if you aren't confident in your work, because you can always get better. Just give yourself the chance to grow, the first step is always the hardest. You aren't alone, either. Like I've said before, there is a wealth of resources and experience here for you to tap into.
So don't be so hard on yourself; it's okay to feel that way, as long as you use it to move forward.