I was quite young - 11 years old - when I had mine out. It’s now many decades later, so I survived.
It’s apparently a straightforward procedure. They give you an anaesthetic to make you sleep. They do the procesure - it’s fairly quick - and you wake up with a sore throat that feels better and better over a few days. I stopped getting so many major sore throats and bugs once my tonsils were out. I still get the odd cold - that’s normal.
After the surgery, it’s nice to have lots of cool drinks, jelly, pudding/custard, warm soup, mashed potatoes, ice cream and popsicles.
I bet it goes well, but I sure understand that you are nervous. Let us know how it goes.