I have not had tests for autonomic functions. I have always been a high adrenergic person...based on my abusive childhood.

It may be PTSD of some kind, or just a hard wired stress response. My endocrinologist at the time of my pregnancy started me (35yrs ago) on propranolol after delivery for blood pressure. When he released me, my internist gave me Tenormin instead.
It really helps me get thru life and stressors.

There is some evidence coming out now, that childhood abuse and stress leaves a permanent mark on the brain. I think I am one of these. I do find magnesium also helps alot, so I use the Morton's lotion daily to aid the Tenormin and keep me at a low dose to avoid side effects.

I did have the experimental 3 shot first Salk vaccine in the early 50's. Polio was pretty rampant in our area at that time. That has become very controversial since they found monkey virus in those people who received that vaccination then. So that may be a factor for me.
I recall my arm swelling up severely on the 3rd booster. So I had some type of reaction then. I was about 8 yrs old.

Therefore I avoid vaccines now.