definitely see a doctor; yes, thyroid sounds liek a big culprit. i have similar symptoms and finally they found a thyroid lump.
but be careful, the endocrinologist I was sent to told me she just wanted to wait and see and so mine has not yet been treated. I met another mom with a similar problem, she had seen the same endo, been told the same thing--but her primary sent her out for a second opinion. The other endo, based in boston, took the lump out right away. She is doing much better.
I am planning to go out for a second opinion and push to get this thing removed. Let me know if you get sent to an endo, I would be happy to let you know the name of the quack i saw so you can save yourself some time and avoid her.