I'm sorry you've been going through this. Have you had a skin punch biopsy? My neurologist suggested it to rule out Parkinson's (I had many of the symptoms). The results did rule out Parkinson's, but they indicated small fiber neuropathy. As I understand it, SFN doesn't show up in EMGs, which I had had. Now we're trying to find out what has caused the SFN, but at least we have a focus, and the loss of the small nerve fibers explains a lot of the symptoms I've been dealing with over the years (severe pain in various parts of my body, fatigue, rapid heartbeat, etc.).

I live near Johns Hopkins in Baltimore and have been seeing a neurologist at their SFN center. Most doctors aren't familiar this problem, so you need to find the right specialist. I finally got somewhere by going to a neurologist, after years of seeing all kinds of doctors for a "constellation" of symptoms. Neurologists do specialize, though, so it's helpful to search for "small fiber neuropathy specialists near me".

Here are some links that might be helpful. Good luck!
https://my.clevelandclinic.org/health/diseases/17479-small-fiber-neuropathy
Anne Louise Oaklander video on SFN