In my experience it is no good thinking you ought to give up but more important to really want to.
I smoked from age 13 to 26. I woke up one morning had my normal cough and wheeze, thought this is stupid. Gave my cigarettes to my then wife and stopped.
I guess it is like anything in life if you really want to you will. Bonus is you won't stink anymore and you'll feel better!
Good luck.