It isn't easy, this from a serious nicotine addict.
I'm always a drink or an argument away from a relapse. That's just the truth. There are lots of people who smoke and quit; but true addicts simply manage. I'll be a lifelong smoker; but have been managing for 5 years with a handful of accidents here and there.
I don't want the government meddling in my business; but this is one drug that should be illegal. The health consequences are devastating and undeniable. If you don't quit, you will die! and it will be a slow painful miserable death, one that you wouldn't wish on your worst enemy.
Take it day by day, accept that you will have accidents; but avoid all those things that trigger them. If you do have an accident forgive your self and get back on track. Have compassion for your self, there is nothing to be gained from punishing your self.
It isn't a coincidence that most people who stop smoking also stop drinking. I gave up hard liquor and only drink beer and wine in moderation. I also meditate, with the hope that it will buy me that minute or two it takes to relapse.