Traditionally, there is NOT much of a gap between a CYOA story and a "straight" novel. The two main differences are that a) CYOA may let you somewhat customize the protagonist (via something called "flavor" text) and b) that CYOA needs branches that APPEAR to be leading to different stories but are, in reality, just brief intermissions before rejoining the "main" story path.
Crudely, CYOA also appears to "move" a lot faster to the reader, so things like breaks and plot points come along faster and more frequently than in linear writing. Therefore, if you wanted to "translate" your novel to CYOA format, simply break up the text into key beats, add choices to each one, and then work to force the reader back onto the main path if they get shunted into a side one.
That being said, there are a LOT of weaknesses to the CYOA format:
1) The customization of the protagonist/flavor text stuff is a nice gimmick, but it can't carry a whole story
2) Too many "side branches" will exhaust the author (and most text will never get seen by the player), but too obviously forcing players to stain on the main route feels like "railroading" and defeats the point of it being interactive fiction
3) Standard (linear) plot arcs rely on standard chronology - a beginning, middle, and an end. It is exceedingly difficult to create "standalone" arcs that aren't based on fixed chronology. This makes it really hard for a story to "develop" without railroading the player.
4) Successful CYOA plotting, therefore, relies on either a) elegantly masking or disguising the "forcing the player to return to the main path" and/or b) creating lots of interesting and engaging stand-alone "mini" experiences that can be combined in different ways without breaking continuity.
Basically, you either end up with a "branch and bottleneck" story that you like because its story arc was interesting and the "railroading" was elegantly disguised (a primarily linear story camouflaged as an "open world") OR a really experimental, sliding doors kind of experiential storytelling where you explore different snippets of text in different successions (each play through). Which can be interesting and fun to read (play), but then becomes closer to something like poetry than true "fiction" in the classic sense of the word.
That being said, if you really want to adapt your story idea to CYOA, here's my recommendation:
1) Find three major MUTUALLY EXCLUSIVE endings that work for your story - this means any one playthrough will only result in ONE of the endings while being open and upfront about you not realizing the other endings. This lets you write 90% of the story as (more or less) linear while only needing to branch out with alternative paths at the end.
2) Reality should always reward the player - if the player decides to shoot the villain, for instance, the story should LET THE PLAYER SHOOT THE VILLAIN, not pull it back at the last second with a "seeing the tears in his eyes, you just cannot bring yourself to pull the trigger" line of BS text.
3) Players react, not the writer - Don't tell the player how s/he feels about something, let the player determine that. Instead, give your players the CHOICE of how to act/react.
4) Use "small" choices, too - These choices might not affect the story in major ways, but they do add impact for the player. Something as simple as having three choices of what to eat for dinner can add a lot of interactivity to an otherwise boring passage.
5) Balance your text to choices ratio - Reading 20 pages of text and then making one decision is a poor ratio. Try making a choice appear every 9 paragraphs or so (or even more frequently).
Everything else is mostly about avoiding the pitfalls learned over 50 years of writing CYOA texts which you can find here and elsewhere strewn across the internet.