Welcome to the boards.
The tests will show whether you have any swelling or nodules, the ultrasound takes all of about 15 minutes and is not painful, not sure about the scan I have not had one of those, but I doubt its painful and probably doesn't take long either.
Have you had any other issues you may not realize are related to thyroid? intolerance to heat/cold, nausea, irritability, weakness or fatigue, hairloss, weight loss/gain, breathing difficulty, heart palps, racing heart? The nervousness can very well be caused by the thyroid.
Did they do any other bloodwork other than the TSH? like total or free T3, total or free T4?
Hang in there and keep us posted.