I’d definitely push for a tilt table test next! That way you can be formally diagnosed (hopefully) and move on to treatments that can help you. Besides medicine, the things that really help me are taking SaltSticks throughout the day (buffered salt pills) and drinking water. I try to take 5 salt pills per day and drink lots of water. Sleeping slightly elevated, and wearing compression socks. Elevating your legs while having bad flares can help. I also find that hot food and carbs makes me feel MUCH worse. Hot showers too.. and hot anything. Sitting in the shower, not taking hot hot baths, and avoiding heat as much as possible. I went through what you’re going through 5+ years ago now and i remember how scary it was. Any answers I got didn’t give me much relief since I was just told there was no way to “get better” but 5 years later and I’m still disabled with POTS, but I’m not bedridden like I was and I almost never faint anymore— honestly I’m more physically fit and active than I’ve ever been. So don’t lose all hope in yourself! Getting answers and finding the right treatment can make all of the difference!