Quitting is a mind set. You have to decide that you're going to and then never consider having another one. If you torture yourself with it and think about it it's only a matter of time. You have to think of yourself as a non-smoker and then live it.
I quit and restarted several times before realizing that I could quit, I just couldn't stay quit. Once I figured that out it was just a mental adjustment to decide never to repeat the cycle. Save yourself some agony, pick a date, psyche yourself up, make yourself sick of them and then do it.