Other than consult an internist or endocrinologist, I'm not sure. Some people don't tolerate apixaban, so maybe the Eliquis is the culprit here. Might be worth a short trial off it, say four days, to see if it improves your sensations and symptoms. Of course, this is only a suggestion and does not qualify as professional advice since I have no medical training. Thinking rationally, though, your risk of a stroke is moderate at worst, probably somewhat less, and if you got the go-ahead from a physician expert in your circumstances and various conditions, you might stand to do a trial this way.

Based on your descriptions of symptoms, I would not thing dysautonomia /Vagal tone are indicated....but I could be wrong. Worth passing this by that internist you're going to see.