I agree with John no one does anything to cause this disorder. It’s just as they say bad things can happen to good people.
I know there are things that can’t be done anymore, but try to find things that you can do that replaces the things you can’t. You mention you like to garden. Can you still pot plants sitting at a table or pick things off the plants if sitting down? My husband loved to garden and couldn’t get down to plant things , but could sitting and potting them . Which he loved to do. The thing is just to find what you can do and not give up living the life you still have.