"It's easy to give up smoking - just don't buy cigarettes".
You joke, but this IS how I quit cigarettes. The impulse to smoke was momentary and I'd reach into my pocket. Not having cigs there, I'd be slightly miffed.
But as I was not buying any, a separate action on which I had taken a clear stance for myself, I ended up not smoking unless in a group setting.
Over time I cut out on that too.
Despite never being a smoker, I know that my willpower is much too weak for that to work.
I suggest training your agency. Read some Nietzsche :3