I have Ehlers Danlos, hyperadrenergic POTS, cervical instability (CCI) and Chronic Intestinal Pseuo-obstruction. I found your post because I get your same symptoms. I'm investigating vagus nerve stimulation to see if moving my gut better will lower my head pressure and put me out of fight or flight, which seems to be causing the sympathetic overdrive and vibration. One key issue for me: "forward head posture" like sitting at a computer while leaning forward, looking down at a phone, or even doing dishes with head down, will cause lots of inflammation in my neck, which then pinches my vagus nerve, and sets off a cascade of symptoms, from internal vibration, to insomnia, dysmotility, heart palpitations, brain fog, etc. One tip I can give is consider eating less salt, if you are not already restricting it. Salt boosts aldosterone, which can trigger adrenaline surges. Taking potassium supplements also raises aldosterone, so it's tricky, and consulting a doctor is wise, especially if you already have electrolyte issues. It's true you could have bacterial overgrowth in your small intestine. Most of us with EDS have SIBO, but I've taken countless rounds of conventional antibiotics (like Rifaximin) plus herbal ones, and only get limited periods of remission, because the motility problem is not fixed. Pathogens in the gut generate toxins, which can slow down motility. For me, taking activated charcoal and zeolite powder binds toxins, reduces bloating, and helps a bit with symptoms.