Abby, This is an exceptional post, and I admire you for being so honest.
The neurotransmitters are really quite nuts. Did you know that too much acetylcholine might contribute to depression? Too much serotonin can cause insomnia?
http://www.psychiatrist.com/pcc/brainstorm/br5812.htm
Since MGers already have an imbalance of acetylcholine, or, rather, how much gets to our muscles, you have to wonder what other neurotransmitter imbalances might follow.
Maybe you're just having abnormal releases of noradrenaline or other neurotransmitters and need to have your hypothalamic-pituitary-adrenal axis checked. Have you seen an endocrinologist recently?
A lot of the psychogenic arguments have a huge chicken/egg component, as you know. Just as that fight or flight fear response kicks in adrenaline, etc., too much adrenaline from a pathological source (tumor) can cause a fight or flight response.
http://www.endocrineweb.com/endocrin...adrenal-glands
It's hard to say if it's truly psychogenic, or if having a doctor say that it was prompted you to relax about the symptoms. Meditation, which makes us relax, too, might be something you want to try (if you haven't already).
That calm balance is very hard to maintain with so many challenges. Even after a couple of decades of doing it, I still have days (like after the flooding we just had) where I totally lose it.
A neurologist I saw once spoke about how those pesky neurotransmitters can cause increased weakness if you become really upset. He wasn't specific about it, so I did some research for you.
Can you and your doctor come up with a way to mentally get rid of MG? Now that would be useful.

Annie
http://www.sciencedaily.com/articles...ous_system.htm
http://www.psychologistworld.com/stress/fightflight.php
http://www.ncbi.nlm.nih.gov/books/NBK28139/
http://www.longecity.org/forum/topic...line-and-mood/
http://en.wikipedia.org/wiki/Norepinephrine (I hate quoting wiki!)