I have POTS and general dysautonomia too, in addition to EDS. It’s been maybe 10 years since my diagnosis. The ‘normal’ drugs didn’t work for me at all, and I don’t do well with lots of salt. Go figure. It’s been trial and error but I think we are finally where we need to be drug wise. My cardiologist is awesome, very open to any suggestion/research I present. I went to the Mayo Clinic for a week long work up of stuff too. But my cardiologist has been my biggest help.
I haven’t had anything to ride for a couple years now, but I was riding regularly for years. Compression stockings helped, especially if I knew I would be standing for awhile. The hardest parts where the prep stuff - tacking up, etc. Once I hwas in the saddle, things were better.
For other reasons (related or not, we don’t know yet), my balance isn’t what it used to be and neither is my coordination. I was lucky to have very laid back, non reactive creatures - in my case mules and donkeys - which made a huge difference. They have been been super tolerant of me and more than happy to stop when I need a break. I don’t think it would have been the same with something hotter. If you have access to a laid back school horse or something, I’d start there.
As hard as it is, keep up with the exercise. Even if it doesn’t seem like it’s getting easier, (it didn’t for me which I find extremely frustrating) I did feel better if I kept up with it. If I missed too many days, I could feel it.
Unfortunately, there isn’t much out there about stuff like this, so it could be lots of trial and error until you figure out a combination that works.
Feel free to PM me.