I know how you feel. My weakness comes and goes like a lightening bolt. I am fine for the most part one minute; the next I am overwhelmingly weak. There is no rhyme or reason as to when it is set off. Just bam. Hit the floor. Since I increased the mestinon to 60 mg 4X a day, I haven't actually hit the dirt.

My old neurologist thought that I was crazy and imagining the whole thing.
I got a new neurologist that took things, like major medical bills from the ER for the results of falls, seriously. I am afraid that he thinks that I am downplaying my symptoms. Maybe I am, because most of the time I am ok.