Your reaction is all too normal. But you gotta get over it. Life is a ***** (censor this) but the only thing that makes it better is each other. It won't be easy.

What you can do, though, is to learn as much as you can and use that knowledge to help your Mum. At 55, she is a young woman. She may or may not have studied up on PD. If she is just going with what her doc tells her she is probably making a mistake because there is so much that the docs don't know. Probably the best or at least the most experienced is a guy named Abe Lieberman. He has been in practice for forty years or so and has treated about 65,000 patients. He has several books out. Get them all.

For your Mum, the single best thing you can do for her is toget her addicted to vigorous exercise. Instead of sitting there thinking of some way to escape, get her to join you in walking, swimming, a stationary bike routine, etc Anything that gets her to pumping. That will do several things but one is that it is the single most effective thing against PD and two is that if you get transferred she will be able to carry on.

There is lots more, but that's a great start. Good luck.