You're taking Mestinon three times a day? At what dose?
Mestinon usually needs tweaking. Sometimes it's the frequency that needs increasing, sometimes the dose amount, and sometimes both.
If you take too much of it (tell me if you know all of this already!), you can get too much acetylcholine and have a cholinergic crisis. A myasthenic crisis is when you don't have enough acetylcholine.
I take 90 - 100 mg. every three hours, round the clock. But that's what works for me. I can't have the other meds unless I go into a crisis. There are times when Mestinon doesn't do enough and my body literally puts me to sleep, usually after running errands.
Don't experiment without discussing this with a neuro, though, okay? Going into a crisis and not knowing why (too much or too little) would be a nightmare if you run into a doctor in a hospital who doesn't know anything about MG. Would they know how to proceed?
I'm really sorry you're going through all of this, without sufficient help.
Annie