newly diagnosed postural orthostatic tachycardia

I presented to our local  hospital with supine heart rates of 95-105, upon standing my heartrate increased to 130-150 within 20-40 seconds.  It may have gone higher but a feeling of impending syncope compelled me to lie down.  The attending stated that I had a case of  POTS and quite an obvious one.  This condition came on over a two week period until I feared my heart would burst.  The attending ordered an abdominal cat w/contrast, chest x-rays, a doppler of the vessels in my legs and an echocardiogram. There were scores of blood tests including thyroid (I have Hashimoto's). I was told the TSH was.01 and Free T4 was high normal.  I have had blood levels like this before but no POTS. The attending and the endo docs signed off on a diagnosis of hyperthyroidism. I am to follow up with the endo but I don't see a connection.  The POTS is thought to me a collection of symptoms of dysautonomia, right.  My speed date with the cardiologist ended in his reassuring me that my thyroid was the cause.  I can't find any such info.  They assure me that we'll fix my thyroid and thereby fix the POTS.  My POTS is completely debilitating. I can stay upright, walk about for a minute or two or take seven stairs and I flop onto the bed heaving and gasping.  I take a beta-blocker but it only keeps the rate down.  The feelings are the same.  I cannot accept that this is forever and I can't find a case like mine or a case where there was resolution.  Thank you in advance for your ideas.