Hi, I am sorry to hear that you are going through this as I know it is not pleasant at all. Yes, I had this in 2007 when the POTS symptoms really took hold and my HR and BP went very low indeed, at one point my BP was 65/32 and I couldn't walk. I also developed neuropathy at the same time. I had lots of brain zaps as I tried to sleep and I mentioned it to several doctors in A&E but no one took any notice of me. For a short time I even had hallucinations. The more stressed I got the worse they became. I had finger and limb jerks around the same time. After a while they settled and I was put on Gabapentin and Nortriptyline which helped me a lot. I had to calm my body down and decided I needed to do something and looked for guided meditation and it really worked for me. After a few weeks things did get a lot better. I had been so stressed that was feeding the fire and I was so anxious and worried about what was happening to me. The tinnitus was bad and I would hear screeching in one ear then go deaf for a couple of hours. I'm guessing it was because there was restricted blood-flow to my head. That improved over time. I wish you the best and if you need some advice etc just message me. By the way, the neurologists told me at the time that it was the way that I was thinking that was causing my symptoms. They were wrong as I went onto be diagnosed with EDS, POTS, neuropathy and I have many other related health problems.