Actually it's not all that uncommon apparently. Here's a website to check out to get you started:
http://www.dystonia-foundation.org/I'm sorry that you had to leave your band b/c of it. It's hard when you have to readjust your life to live within the restrictions of your disease, and accept those limitations. The best thing you can do is educate yourself as much as you can about your illness--there's a lot online--find a support network, whether locally or online, and do what you CAN do, rather than dwelling on what you can't.
I have a chronic autoimmune disease that I've lived with for 28 years. With the help of some rather nasty drugs I've been in remission for 5 years, but I'll always have the spectre of it hanging over my head--it could come back at any time. So I don't push myself physically as hard as I used to, I get enough rest, don't mentally/emotionally stress myself--I've learned to live within the limitations of my body.