Quitting smoking sucks.  I smoked 2 packs a day and quit cold turkey.  After numerous tries, it finally took pride to get me to quit.   My buddies told me there was no way I'd ever succeed, since I never had in the past.
The resolve to prove them wrong was enough.  That was 10 years ago.  The key for me was to just do it one day at a time.   Every day I'd decide I couldn't do it, so I'd promise myself I'd start back tomorrow, but I HAD to finish today smoke free.  Just the thought of having that cig "tomorrow", got me through "today".  Then I'd do it all over again.