I agree with Oleander about the thirst. I know that's the last thing you want to hear.
But my friend has diabetes and Hashimoto's, and the doctor told her she had to get her diabetes under control before he could treat the thyroid. I have been following your posts, Pursie, and I know you are having a terrible time finding treatment that works--that's why I was wondering if something else is going on, too. I know adrenal problems and diabetes are two that have to be treated first. Not saying you have those, of course--just that it would be good to get it checked.
The thyroid problems we have have symptoms that are similar to many other things, including diabetes--that's why you might want to have your blood sugar checked like Oleander said. Here are some symptoms of diabetes: unquenchable thirst, frequent urination, fatigue and weakness, numbness or tingling in hands and feet, blurred vision, skin that is dry or itchy. I've noticed that some of your symptoms are like my grandma's when she hasn't had her insulin--she even got "starey".
Anyway, take it for what it's worth.
Which might be nothing. Ha ha. Just trying to help...