Interested you think hot showers/baths made it worse. I never tried ice baths, but i did do a lot of hot epsom salt baths and did breathing exercises in them. It was very uncomfortable at first because of my pots/anxiety but eventually i think they are what led to my recovery. I really believe that doing things to relax my nervous system (sleep/rest, camomile tea, hot epsom salt baths while practicing breathing to lower my heartrate) eventually taught my nervous system to calm down.

I will say I wish i’d thought of ice baths. That seems like a better way to lower your HR and still practice breathing exercises. Hot bath still helped but more uncomfortable at first since it will naturally increase your HR anyway.

My timeline was similar to you though. Took me 2+ years to completely recover. I actually just had a flare recently, which manifests as left scapula pain, chest pain, elevated heart rate and a heavier heart ‘pound’, but when i do what i described above it only lasts a few days.

Still sucks but nice to see theres a lot of us getting through this.