I've had a thyroid biopsy done, it isn't that bad. They ultrasound your neck and find where they want to take the biopsy from then numb your neck with some novacain and when you are numb they put in the needle, there was no pain, but it felt kind of weird when the moved the needle up and down to get more cells.
I have also had my thyroid removed due to thyroid cancer, the surgery wasn't hard at all, and I went back to work a week afterwards. I could have gone back earlier but was feeling lazy and enjoyed my week off.
Feel free to pm me if you have anymore questions. Just try to relax and remember that they thyroid is very replaceable with the drugs they have now, I don't miss it a bit.