I quit on December 5th and have not looked back. Did it ice cold turkey-style and distracted myself with lots of online video gaming, more walks where there are no stores, more sleep and less hanging around smokers.
After smoking for over 25 years, I was worried I'd never be able to quit. I'm glad so say I was wrong. If you're thinking that way, you're probably wrong as well. I hope you are and that you can quit despite it being hard.
It's only difficult for the first week or so. For me, getting past day 1 was key. After the first 24 hours, it got easier... er, less hard.
Now, only 2.5 months later, it seems like it was a lot easier than it felt at the time.