Yeah, I've witnessed this first hand with my spouse. She's been told she just needs to exercise more (she was a professional dancer when it hit her), that it's all in her head (actual psychiatrist said otherwise), that it will resolve in 6-18 months (it didn't), etc., etc. It's pretty appalling.

Thanks for mentioning POTS, btw. Despite how many people have it, it's still fairly poorly known about even within the medical community.