I had a professor that always liked to bring home the point of "
It takes 21 days to change a habit." Now wether or not that number is scientifically true or not isn't really the point here. The point is habits formed over years and years of time will often take time to change.
Anyone who has cut their cigarette consumption down from XX per day to X per day has still accomplished something, and you need to focus on that positive aspect of it. Don't say "I'm still smoking X per day." Say to yourself "I'm no longer smoking XX per day." When you put it in that light (The so called glass half full theory) it may help with how you feel.
For me, I think my ADD really helped in making the switch. Something new and shin...oh, what's that on the wall over there.