Weed is tricky because it's not as damaging as alcohol or other substances nor are the consequences anywhere near the others to most people. So if you want to quit when you get the urge you really have to figure out a either a feeling the drug gives you that you don't like or something it may lead to that would have serious consequences.
I just always tell myself that if I smoke I know eventually I'll get bored of it and go right back to drinking or worse. That may not work for you but something like that maybe? Think about lung cancer or increasing anxiety or how it is making you smoke when you don't want to, the amount of money you'll save etc....