Hello hammerklavier: At 24, you have a lot of years ahead of you (presumably.) Your parents may be supporting you now. But this is unlikely to be the case for whatever amount of time you may have left on this earth. Plus, in our society, a lot of people's self-worth derives from work. So I think for both of those reasons trying to work, if you can, is important.

If it turns out you can't work... then you can't & at some point you'll probably have to see if you can qualify for SSDI. But that's not at all a sure thing either under any circumstances. My suggestion would be to either start out by doing some volunteer work on a regular basis or perhaps get a part-time job. Then at some point perhaps try making the jump to full time. Better to start small & work up than to try to go full-bore all at once & risk having the whole thing unravel.

Learning piano repair & tuning sounds great! I'm not familiar enough with the profession to know to what extent one can earn a living wage doing that. But it sounds as though it would be something that would be in line with some of your interests & that's important. Perhaps later on even college could be a possibility. All things in good time, as the saying goes. Many years ago, I had an opportunity to attend the Boston School of Music. I was talked out of it by my parents & teachers. It might or might have worked out for me. But I always hated what I did do instead. Don't listen to the naysayers...