It started to kill my lungs and I had to quit. It wasn't terribly difficult for me probably due to the fact that if I kept at it I felt like I was going to keel over. My willpower has maintained pretty well, though I've had one or two here or there at a friend's house or something. But I always regret it on some level and have done pretty well just keeping off it entirely. It's been several years, not really sure how long... and I did go back to it for a brief while after the initial quit. Actually, and I'd quit for several years before my divorce, but that started it up again. I used to really abuse them in order to de-stress (which is stupid as hell considering the effects on the body).
Keep at it, man. Shit is terrible for you. Most of the companies are also using continually more toxic stuff as they go, GMO tobacco, and they do some pretty awful animal testing.