I'm glad your daughter is so close, and that you are there to support her. Just this extended family living situation alone is going to make everything much better for her, no matter what is happening. And I think better for you too, because you'll always be able to reach out and help.
As the mom of a grown daughter I can say that her suffering is my worst fear, my weak spot, my worry. She is partially disabled from a car wreck where she was hit, as a passenger, by a drunk driver. I do focus on reminding myself that she is a very competent adult with a wonderful family. She lives near-by, and we actually work together professionally. It has take much thought--and therapy too--for me to detach from my worries about her. I hope therapy will let you focus on taking care of yourself, too. And I really hope that things go well medically. I'll be thinking of you, and check in when you feel like it. Is there anything right now that helps you--taking a walk, funny movie, that kind of thing?