Is it bad that i've smoked cigarettes after having sinus surgery?

Yes: Smoking is a respiratory irritant, and should be avoided after sinus surgery. Additionally, it can inhibit healing. Stop!

Yes: Yes. The reason you had sinus surgery was to make your sinuses and your nose better. After surgery it takes a while for the sinuses and nose to function normally and part of that is for them to become self-cleaning. The way they clean themselves is with cilia and this cilia is damaged by cigarette smoke. You significantly decrease success of surgery by smoking.