Good Luck!!
You just have to believe you are not a smoker, I found if someone offerd me a cigarette and I said 'Oh, no thanks...' they (and my lack of will power) could usually persuade me in the end. If however I said 'I don't smoke' it reinforced the 'non smoker' part of me...and I didn't give in to the craving (as much).
I have heard that it's not only the nicotine addiction but the 'actions' your body becomes used to that make it hard to stop, so I used to keep something in my hand to fiddle with - a bit like worry beads.
One year now almost completely smoke free (I've slipped off the wagon a couple of times - but didn't make it an excuse to start again) and I feel *so much* better. It's so good to be able to get to the top of a hill without gasping for air!.