1) you were probably told that nicotine rubbish by some HCA or something. its bull****.
2) the important thing is you'll be having an operation. smoking makes your blood more likely to clot up, makes healing take longer, and reduces the amount of oxygen in your body. If you totally cut out smoking from now until a few weeks after the operation (you wont be in the mood for fags after it anyway!) then that would be ideal. but you should make sure you don't touch a ciggy for at least a couple of days before the op anyway. thats how long it takes to get your blood clotting up to more normal levels.
obviously this advice is more for bigger ops rather than tonsil, but it still applies.