You are stressing yourself too much, calm down. I know it is hard when you are feeling bad and all sorts of things run through your head, "been there done that". Just relax and when the tests come back post the results along with the lab ranges, IF it is not a thyroid problem then you go on from there looking for an answer but at least you have ruled out thyroid.
Have you ever had your blood sugar checked? Dips in blood sugar can also cause strange symptoms, I know, "been there doing that" too, I am hypoglycemic as well as having a thyroid problem. A lot of people think of low blood sugar as getting faint or dizzy if you don't eat, but it can also cause panic attacks, anxiety and a whole lot of other problems.
For now, take it easy, don't get too upset, if you need to talk just pop on here and vent for a while, we are all here for support.
Have a great weekend