Hi B.,
I will warn you that my post is not going to be sugarcoated....
I had my tonsils and adenoids removed when I was a teenager, and I remember feeling downright awful for the first week, and then not-so-hot for the second week. I have never had a c-section so I can't compare, but I remember the pain being pretty bad.
As others have pointed out, you will feel very weak, in large part because you can not eat anything solid. Since you have 3 small children, I would advise you to have someone come over EVERY DAY for the first week to help you out. You will be in no shape to take care of your kids, and you may very well need help taking care of yourself.
I hesitate to share this because it is graphic, but after a tonsillectomy, you will puke up the dried blood that collects in your stomach during surgery. (The doctor will tell you this if he/she hasn't already, so it's not exactly a secret.) It is nasty and it hurts your throat like hell. I remember getting sick on the kitchen floor, and my mother--who was a nurse's aide and had seen it all--was so grossed out by it that she ran into the other room gagging, and I was left to clean it up myself.
And you know what? My tonsils grew back a few years later. ;-)
Good luck to you.