After 9-10 years of smoking, I'm at 6 months smoke-free on Friday.
The thing you have to wrap your head around is the thought of NEVER doing it again. If you still harbor the thought that someday, you *might* get to have one again, it will wreck the whole thing. It's like coming to terms with the death of a loved one, or something.
One thing that worked for me is telling myself to man up and not wuss out and give in to the temptation, really psyching myself up about it. Nothing personal against smokers, of course, but if you keep telling yourself you're better than that habit, you'll start to believe it.