I read somewhere that it's easier to quit when you're also trying to lose weight. I have no idea where I read it or what the explanation was, though. I suppose maybe because you're already focused on one goal, you can use that on the other one, too? My english isn't good enough for this, sorry.
I stopped smoking last May, but it was easy because I got an e-cigarette. I get the nicotine (although it's lower now), I get to keep the habit, so I'm not afraid I will end up smoking to replacing it and I've even replaced coke with it because my e-liquid tastes almost like it, lol. Have you ever thought about getting one?