I'm so sorry things did not go as well as they could have. Your symptoms of MG sounded fairly serious. Are you better?
I try to throw stress into the trash with the rest of the garbage. It's just not worth it. And I know I've said this before but it's worth repeating. People who love you do so because of who you are and not what you do!
My family got together just to decorate cookies. It was fairly simple and even though I couldn't eat the cookies (celiac disease) or decorate for long (hand cramping up), I could still enjoy watching everyone else do it. And we did it way before the holidays. It worked better for everyone's schedule that way. I think the getting together part, no matter what you do, is the important thing.
We all need to feel that we are loved, especially during the holidays. I'm sorry that this time is so stressful for you, for so many reasons.
Do something super nice for yourself, whatever that might be for you.
I do have to add that I went to a person years ago who taught me how to meditate. I can now instantly go into a state of extreme calm. I can't tell you how much that helps during times of stress.
I hope things get better soon.