Sounds tough, but I think you're on the right track. My stepson broke his pelvis (and a bunch of other stuff) in a car accident. He tried to use a stationary bike in physical therapy and just couldn't ride it for more than a few minutes, and he sas so sad that he walked out of PT and never went back. But a few weeks later he got on his bicycle and got his strength back by riding. It didn't really take as long as thought it would. I hope things go as well for you as it did for him.