WELCOME TO THE COMMUNITY!!!
Sometimes Hypo and Hyper symptoms are so very similar.
I suffered with hyperthyroidism and had fast heart rate, severe anxiety, cramps, aches and pains, weight gain.
I have also had these symptoms when drug induced Hypo before RAI and after RAI getting my dosage of thyroxin stable.
If you have TED (thyroid eye disease) then the antibodies can accellerate the TED so keep a close watch on that.
I may be wrong but hear so of many people with TED who dont suffer severe symptoms with the thyroid but do with TED.
Ask your Doctor to do the antibodies test for BOTH.
I wouldnt be happy until I knew 100% what was going on.
I have also had 'crossover' symptoms of both Hyper and Hypo too.....
Very confusing as I couldnt figure out if I was hyper or hypo then found that when I got the 'crossover' symptoms, it was usually my FT3 was high (Toxycosis).
There is so much involved with the thyroid and any form of stress or upset can also affect the levels.
Sorry I cant be of much more help.