I see a physical therapist who specializes in Long Covid, and one of the things she works on most is POTS/orthostatic intolerance. She's helped me a lot. She started me on exercises to strengthen the area between my neck and my knees, the place where the blood pools (when it's supposed to be pumped to my brain . . . ).

You can search YouTube for videos about exercises for POTS and find pretty much everything she's had me doing. I like working with a PT because it keeps me accountable, but doing the exercises yourself would probably still help.

I wonder if Long Covid meds might also help your POTS.