It was a really long road for me. When I was 28 I stopped smoking by using Zyban -EXCEPT for when I drank. That was my caveat and still allowed me to smoke 1-3 times per week. Granted, it was much better than how much I had been smoking, but still not good. I thought pregnancy would be the cure, but as excited as I was to have a drink with friends after both of my pregnancies -I was just as excited to have cigarettes with them!
Finally in the last year I have completely stopped. For me it's been a combination of really starting to hate the way it made me feel and hating myself the next day for doing it because I really was feeling like -even though I wasn't smoking more than once or twice a week -it was going to wind up killing me. I've really gotten back into running. I could run easily as a smoker in my 20s and in my 30s -although I started feeling it more in my 30s. I'm 42 now, and if I smoke on Saturday night, I can still tell if I'm running on Wednesday. Quite honestly I just had to really be ready to completely stop. Now that I have -it's great!
I suggest you speak with your doctor about some of the products out there that could help you. Zyban helped me get rid of all of my smoking habits except for the drinking one. People sometimes didn't believe me, but I HATED the thought of a cigarette or smelling them if I wasn't in a bar or drinking. I never wanted one in the morning or in the car or during any of those old "habit" times. They've come out with a lot more things to help you in the past 10 years. I would check some of them out!