I'm older than that! I may be the oldest person on Steemit. But I remember 39. I had not yet 'found' myself, either. Some of us take longer; some of us are really complicated :))
I hope you get on with the book. You know, I wanted to write all my life and never really did. And then, when I was over 60 (!!) it started to flow. I learned that if I didn't dwell on the project, but just began an outline, somehow the tension was broken and the words came to me. It's just a little trick, but if you sit down and don't think of it as a book, but merely as an outline, you may find yourself in the middle of something really productive.
I'm not underestimating your struggle. But you haven't given up. That's the important part. As long as you're fighting for what you want, the road is open.
I didn't write anything in response to the choice question. Got hooked up on trying to insert the picture of a child into a seascape. Hours and hours of that. But it's done. Never, ever give up :)).
Hope you have a peaceful day.
Your friend,
AG