I believe we all went through this (very hard) phase of realizing that we just can't do what we (easily) did before.
I have said many times that one of the hardest things about this illness is that you think you can do what you really can't.

You found yourself on the floor struggling with the Turkey, and I found myself in my clinic with the patient in my room going to call someone for help, instead of me taking care of him.

Or was being gently told by one of my colleagues that even if I don't mind being totally out of breath after performing a routine procedure, it does scare my patients.

It took me time to find the core-what makes me able to be the same person for my family, patients, colleagues and friends. Even if I can't physically do even a margin of what I was able to do before.

And it took me even longer to be able to honestly admit to myself and to them how frustrating it can be at times.

And it's not you that is crazy, it is this illness.

I also think you should tell your neurologist that you are overall not doing better with the mestinon. ( Do you happen to know what type of MG you have?). Don't be too stoic about it, because things can get worse.