Struggling to understand if my symptoms are caused by real disease or by my mind. I have been dealing with this for over 9 months, but after many negative tests, one has to wonder...

It started with my wrist/arm and weakness/numbness. I was told I had extra cervical ribs and that I had a pinched nerve. I did 3 months of OT and PT. The only improvement was from the short course of steroids I did during that time. Things plateaued... it wasn't much better or much worse. It moved into my left arm, but still not too much. I saw a neurologist eventually and had a negative EMG and a negative cervical spine and brain MRI. I decided since everything was normal that I needed to just chill out. I asked if I could have a conversion disorder and my neuro didn't think it was likely, but he appreciated my desire for my symptoms to be harmless. So I just kept on keeping on.

Then 2 months ago, it started to become increasingly difficult to climb the stairs, wash my hair, run, empty the dishwasher, etc... It got worse as the day wore on or if I exerted myself excessively. Saw the neurologist again, and confirmed that I now have significant muscle weakness - especially in my legs. I had another EMG, evoked potentials, another MRI w/contrast and tons of blood/urine. EMG, EMG w exercise/rest and EEG were normal, regular MG antibody test was normal, and waiting on everything else. In the past 3 days, I have developed jaw fatigue as well as excess saliva. Chewing and swallowing only seem to bother me at night. I gagged tonight trying to swallow the Mestinon! That was after trying to eat a raw carrot

The neuro wanted me to try Mestinon... 60 mg x3 upsets my stomach but actually seems to mitigate, not eliminate, my symptoms. Improves my grip strength and seems to reduce the heavy, fatigue feeling in my legs - especially at night. I know that Mestinon can improve anything that affects the neuromuscular junction, so I'm not sure that it tells me anything. I tried taking only 30mg and didn't notice anything. I am wondering if taking something is just placebo? Maybe because I want it to be.

My symptoms seem to point to MG, but how could I have this if all of those tests are negative? I have not had a SFEMG, which I have read about on here, but don't really understand how it could be different from what I've already had. Bueller? Bueller?