I know tonsils and thyroid are not near each other. But, most important is to be in the care of very experienced doctors. You don't have to like them. Just trust them.
I am 72. Had a complete thyroidectomy plus neck dissection. 35 radiation to that area. Plus 6 chemotherapy boosters.
You are undergoing treatment one day at a time. I was on a liquid diet for 2 months. I hired someone to drive me to and fro treatment.
Make the best choice for your health. Don't decide based on what you think you can get through.
Peace and virtual hugs.