My symptoms are almost exactly like your, especially the exhausted by Friday and still working. I am sero-negative but I got a diagnosis of MG with a SFEMG. I would suggest going to a large teaching hospital and see a neuro-optomologist. That is how I got my diagnosis. They see MG all the time and they treat more aggressively.

I felt an immediate improvement with Mestinon.

Let us know how you make out
kathie