Four and a half years ago, I was kinda out of athletic shape and a smoker. I smoked about 1/2-3/4 pack of Camel Lights daily, ate junk food, and really didn't take care of myself. Got a mountain bike, started running some, and eventually bought a road bike. By summer of 2004, I was going two to three days without a smoke, and on the days that I did smoke, I had maybe 5-8. By December, I was putting in 150-180 mile weeks, getting in good shape and I was finally off the smokes. Two months later, I entered into my first race, a brutal 55 miler in February, and won in a solo breakaway.
Now I'm a Cat. 3 racer, occasional runner, and in pretty damn good shape, if I might brag. I'm doing 180-260 miles a week and can climb better than I can sprint.
I still crave a smoke sometimes, though. If someone walks by with a cigarette and I catch a whiff, my mouth waters a bit. It is right now – which means that the addiction hasn't really left. If out with my friends who smoke, I might take a drag or two off of their cigarette, but it hurts so bad to do so, so I usually don't.
Either way, I'm not a smoker now, nor will I ever be again.
Good luck on quitting. You're gonna need a little, but it sounds like you're doing alright.