Hi! Yes, I have this too! The only thing that helped the myoclonic jerking symptom was Ativan, unfortunately. Well first Valium, and then when I had to up the dose, I went to Ativan. I only ever took it at night, but went up to 5mg. Now have lowered my dose, and am on 5HTP, and L-Theanine along with .5 Ativan at night. I only get the twitching if I try to sleep. And it is all over my body, not just legs. The annoying thing about this is that most sleep tests only test the extremitites, and they will diagnose 'restless leg'.
Mine started when I got food poisoning (or so that's what I think it was) and was in the hospital for a few days. That was in 2003. It was intermittent, and now it is all the time. I also get that crazy reactivity that you wrote about, if I'm trying to fall asleep, and hear a noise.
I think this has to do with cortisol levels (adrenal).
Of course the lyme and possibly co-infection underlying it all.
Minerals, I also have this 'pit of stomach' feeling (I also believe it's in my throat). When I wake up, it is there. Feels like a sadness or emptiness, crazy. It started when I believe I got infected, I was in grad school, outdoors all the time. It turns out that on endoscopy biopsy, in duodenum they found Mycoplasma Penetrans PCR. I think that may be the culprit, haven't adequately treated it yet.