I'm newly diagnosed by a friend who is a physical therapist, but not a doctor. I've just started my research and thought I maybe be able to get some advice here. I am a musician who has no option but to have my arm in a bent position. When I play is when I typically have numbness and weakness in my fingers. Is there anything I can do during those times when I'm playing to help prevent the finger numbness?

I am also a musician. Unfortunately, there is no instant cure, temporary or otherwise, for numbness, pain and tingling. I can only suggest you go to occupational therapy twice a week and reduce the amount of playing you do. Practice those exercises that the OT will give you and hopefully your problem will be solved.