While you're getting tested for Myasthenia, BE SURE and have your doctor add a Celiac Disease screen to your bloodwork. It's possible to have both at the same time - if you have a gluten intolerance/sensitivity, eliminating gluten from your diet can help ease some of your symptoms.

I'm not suggesting that you don't have MG - I got the CD diagnosis first, so I was already on a gluten-free diet for a couple of years before my MG diagnosis. I do think that the GF diet has made my symptoms less severe than they might have been otherwise; unfortunately, if a person has had undiagnosed CD for a long time there is some damage that can't be reversed.