I have TMJ and , although i dont think i clench at night, i do get weird sensations....was trying to figure out what it was from ( have a cyst on my spinal cord that gives me random symptoms) How old are you? Old enough to drink? If so, i was wondering if when you drink alcohol, do you get really dizzy and out of it? TMJ does weird stuff i guess...stupid jaw
oh and what antidepressant? I have to take Lyrica once, and lexapro, and remember those same symptoms, almost like your upside down, all the blood goin to your head....twitching. Its on the left side of my head as well...but im not taking any of those anymore and i still get it
Because of the pain in your neck, I think you should make sure your cardiovascular system is alright. Recently watched an old TV episode where they guy was having pain in one side of his neck. He wound up in the story having a heart attack (not fatal one). Could have nothing to do with what's wrong with you, but the carotid artery does pass up that way. It's nothing you want to wait around too long on to rule out!
I have TMJ disorder, and this can lead to migraine headaches (a lot of times one side is worse than the other). Since you clench, you may want to consider getting a hard flat-planed splint. I have one of these to try to keep the arthritis in my jaws from getting worse and it helps with the headache issue quite a bit, although I am still a migraine sufferer. Last time I went to bed without my splint, I woke up with a bad headache!