I have a close friend named Rob whose mum had thyroid cancer and genetic testing said he was sure to get it as well. A few months ago he had a tt and I was invited to visit, I believe it was not the day after surgery but the day after that. I expected him to be tucked up on the sofa in his jimjams, but he was fully dressed, making lunch and walking around as though nothing had happened. His incision was uncovered and barely noticeable even then, and in the intervening months it has faded to nothing. You wouldn't know it was there if you weren't looking for it.
I asked him how he feels now and he said immediately after the surgery he had some sluggish-gut issues (just getting accustomed to the levo I think, and a reaction to the anaesthesia) but that has sorted itself out.
He has always been a very high-energy person, so I was concerned that he might have to make adjustments after surgery, but he seems as full of energy as ever. He recently sold his house and the last stages of the process went faster than expected; one day I got a text out of the blue saying he had already moved, which can only have taken a few days with little preparation. I can't think how he managed that.
His mum is also doing well, though she did have to have chemo. Although Rob's surgery was meant to be preventative, they did find some cancer cells in the lab, and it was early enough that he needs no further treatment.
I hope that helps. Good luck with your surgery!