I've had a really bad childhood and experienced a lot of severe emotional trauma throughout my life since then, including at that time.
I do think that what you have can be caused by severe emotional trauma. If that's the case it basically explains why the tests that doctors run come up empty.
There are defense mechanisms that the body can use in cases of trauma that lead to reduced blood circulation which in turn messes up temperature regulation and shows itself as low blood pressure.
That means that the first step would be to move to a safe environment where you aren't constantly exposed to severe emotional trauma. Did you already make that step?
Previous Open Thread
You know the drill - If it's worth saying, but not worth its own post (even in Discussion), then it goes here.
Notes for future OT posters:
1. Please add the 'open_thread' tag.
2. Check if there is an active Open Thread before posting a new one.
3. Open Threads should start on Monday, and end on Sunday.
4. Open Threads should be posted in Discussion, and not Main.