I also have hypothyroidism and have taken Levo Thyroxine tablets daily for over nine years, although the thyroid was not removed. I have never had the symptoms you describe and agree with Sqad that it is unlikely to be the cause, but you should have a thyroid function blood test each year at least. It allows any fine adjustments of the dosage to be made. Mine came down from 150 mcg daily to 100 mcg per day plus 25 mcg on alternate days. As long as you're absolutely honest with your GP, it will have a much better outcome, I'm sure. Good luck.