Logic Impairment, Short Term Memory Impairment, Muscular Weakness. Diagnosed With Fibromyalgia. Myasthenia Gravis?

Question: Myasthenia Gravis? :

I have had various intermittant neurological problems for around 20 years across many systems - cognitive (more rare)[word choice, slow speech, logic impairment, short term memory impairment], muscular weakness (common), slow rhythmic tremors (mostly resting), migraine (common), hypersomnia (fairly common), urinary urgency/incontinence (more rare), blurry vision, etc. The muscle weakness and burning/pain is much more prevalent right before menstruation. Symptoms can be pretty severe (multiple falls, etc.). Muscles fatigue quickly, then recover when resting. Sometimes muscles are so weak they are limp and it requires my arms to stand, lift my legs, and sometimes I can't grip things or take wet laundry out of the washer. My muscles sometimes are tense on their own and the tension builds and they jerk. (Feels like restless leg, but can happen at any time.) I also was diagnosed with fibromyalgia in my early 20's (I'm 43 now). I use a cane fairly regularly to walk and have for around 15 years.

I had discounted MG because it usually occurs in eyes and face most commonly. However, more research uncovered that it can occur with minimal eye involvement.

I have not seen any cases with tremor in my research though.

I did a year long diagnostic process with a neurologist at Barrows in 2009. My symptoms were waning at the time and she didn't find anything through blood tests and MRIs. She did some sort of test for auto-immune with bloodwork, although I don't remember what it was. I did not have an EMG test though.

My GP is recommending further diagnostics with a new neurologist. Before I dive back in to diagnostics again, I want to dig around a bit to see what venues might be good to focus on, because I'd really like this to be productive. Does this seem like a likely candidate? Do tremors rule MG out? Or, alternatively, is it possible that MG is co-existing with another disorder causing tremors?

Thanks for help with my speculations.
XXXXXXX