Y.B.
I don't know anything about CAH but your story was heart wrenching for me & as I read over it a personal trainer popped into my mind. Do you think that might help the situation some? Share with him/her your concerns & maybe give them some info on it & they may be able to work out something for you to help him. You've been blessed to have a blended family & it sounds like it's working, good luck to you & God Bless!