Re: questions about TSH
"within normal limits" doesn't mean much. Do you have the actual results and the lab ranges?
If they are low-normal, I would suspect pituitary or hypothalamus problems. and would start treatment for hypothyroidism while seeing what else might be low.
If they are high-normal, I would suspect hyperthyroidism and would start testing thyroid antibodies and consider a thyroid scan.
If they are at the middle of the range, I would say that you don't likely have a thyroid problem at the present, but that it might warrant getting antibody tests done and watching the other levels for a while, in light of your symptoms.
I am not a doctor, nor have I ever played one on TV...