I was diagnosed with POTS in 2007, and I too was diagnosed after having an eating disorder. I was told at the clinic I was at that my orthostatic hypotention and my sinus tachycardia was because I wasn't drinking enough, so after they made me drink 4 gatoraids a day, and a blood test, they realized that I wasn't dehydrated. Upon my discharge I followed up with a cardiologist and was finally diagnosed. I was placed on Midodrine and it helped a bit, I was then diagnosed with AVNRT and had an ablation. The ablation helped at first a lot, but, now I feel like it's all coming back again. My heart surgeon said that it was very unlikely that my AVNRT could come back, but I'm super confused as to why after 6 months of my POTS symptoms being awesome, they are starting to come back again. I can't stand up for a long time, and I have had to go back to using the bracing harness on my service dog. (for a while, he only needed to do tasks related to finding someone if I fainted, or retrieving objects, especially dropped objects so I wouldn't have to bend over and risk fainting...) But yeah, very stressed, as since the ablation, the Midodrine doesn't work as well.