It sounds like Myasthenia gravis. Your body started to produce antibodies to acethylcholine receptors (?). Try common treatments for this condition. Maybe immunosuppresants like glucocorticoids? Have you tried this?
Well, I do not have most of the symptoms at all of MG. I do not have facial paralysis, difficult swallowing or chewing, coarse voice, double vision, trouble talking, altered speaking, limited facial expressions, etc.
This wouldn't explain how CDP Choline (or possibly Choline Bitartrate) long-term decreased my insane sensitivities. Before that both Ashwagandha (decreased) and Chamomile (increased) them short-term.
I was able to uncover this little nugget:
This has been noted in a living system, where aged rats given 100-500mg/kg CDP-Choline daily for 7 months experienced a 6-17% increase in muscarinic acetylcholine receptor concentration (whereas control experienced a decline) although affinity of the receptor was not modified.
And I still think I have a type of POTS Syndrome based on my symptoms (even though tests results were inconsistent):
...screened over 150 POTS patient volunteers and healthy controls for three different muscarinic receptor antibodies. These antibodies are known to be associated with dysautonomia, and were found in more than 87% of POTS patients in a smaller preliminary study...