Hi, AlmostEasy.
I think it's quite dangerous to be self-medicating, especially when you don't know exactly what's wrong yet. Also, some of these OTCs interact with each other and could make your situation worse.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3573577/
http://umm.edu/health/medical/altmed/herb/astragalus
I won't even comment on what you should or shouldn't be taking.
You need to see a neurologist to evaluate what's going on. And probably an internist, too. And to fully assess any endocrine/hormone issues, an endocrinologist would be best.
You could ask about having your B12 and D levels tested. Maybe even the celiac disease antibody panel.
There's no way to tell if you have MG. You might have more than one thing going on. You need a smart internist to direct your care and get you to the appropriate specialists.
I hope someone can figure it out for you.
Annie