I just quit smoking at the beginning of November. I smoked for 5 years, from 21-26, smoking 2-3 packs a week. I was starting to get my yearly winter cough and shortly after that I got sick. I was too sick to smoke for about 4 days. After that I said fuck it, I'm just gunna parlay this into quitting altogether.
It is all about breaking habits with quitting. Another thing that helped out is they banned smoking in bars in Virginia right around that time. Once I broke the habit of a smoking after eating, it was clear sailing.
Looking back I don't think I'll ever smoke again. I feel so much better physically since quitting. No more cough.
Good luck kicking the habit. The sooner the better.