I've done the methodical climb back myself - not as a story, as a season.
Two cycling crashes, four months apart. The first put me on the ground hard enough to be treated like a motorcycle wreck. The second came on my first ride back - the day I got my bike out of the repair shop. After that, the fitness was one problem and the fear was a bigger one; there were block rides I finished shaking.
So I rebuilt it the way I'd coach anyone through it: small, repeatable, evidence over feeling. Outdoor FTP tests again. Descending again. Then the speed came back, and so did I - I'm back to hitting 47 mph on a descent and pointed at my next Ironman start line.
That arc is why comeback athletes are who I coach best. I know exactly what the bottom of that curve feels like, and I know the way back up isn't motivation - it's a process you can trust.