Hi. new.
I have the same thing. Low BP all the time, even with salt, 3-4L water per day, compression stockings.
I'm also light-headed a lot of the time. I noticed my BP goes down after I eat, and that's usually when I start to feel worse.
It started for me after a concussion/moderate TBI early last year. Before that I had gastroparesis, and would feel crappy and tired after I ate, but I never checked my BP. Then after the concussion, it got 100x worse. It is so bad that I thought I was concussed for the past year, my doctors didn't know why it wasn't going away. But after I did a fast for a 3 days, around a month ago, because I noticed I felt worse on days where my gastroparesis was flaring, I felt FINE. Like my old self again. So now I try not to eat until later in the day, so at least I have some dizzy-free time in the day. I think it's postprandial hypotension from dysautonomia from my concussion, but my dr isn't sure. She says she doesn't know enough about it to say either way. So now I'm looking into specialists she can send me to.
Oh man that was long. Anyhow, I think we have similar symptoms. Let's keep each other posted about what happens.
Also wondering, do you feel worse after you eat? Have you noticed it's worse with certain types of foods? Anything that affects it?