have you done a search on the web for tcc practitioners or Chinese medical doctors who have treated someone with Parkinson's?
Can you stand for any period of time? Can you walk stably? If you can, you might just want to try a normal tcc class.
I don't know that much about Qigong, but some of those exercises might be helpful.
I think one thing that's very important is for you to keep a positive attitude. I'm not a doctor, but as a tcc practitioner, I will say that mental attitude, calmness and relaxation are critical to the art. And, I suppose that some people say that they are conducive to health.
I really don't have any answers for you. But I sincerely wish you the best of luck.