You have a lot of symptoms that I am not familiar with. However, some I am. The eye drooping, the speech, breathing and tired, are symptoms I have had. I do have MG. Confirmed by blood test. I would try another Neuro. My 1st one missed MG, and tested for everything else. besides there are different types of MG, that do not show up on a standard antibody test.
You will most likely hear from people on this board who have more Medical knowledge than I do. Maybe they can help more.
Good luck and get better
FREDH