what are some good ways to quit smoking?

im 21 and i started smokin at 15. it was the STUPIDEST decision of my life. i have tried quiting in so many ways nut i cant quit i tried Nicolette gum, nicotine patches, and cold Turkey . I herd about champ ex my doctor said that 90 percent of the people that take champ ex quit smoking but it can have bad side effects such as depression. has anyone here been an champ ex, and give me some good tips on how i can quit smoking.

How long will withdrawal symptoms last if I quit smoking after smoking half a pack a day for three years?

I’m 23 and have been smoking half a pack of day for almost three years. I plan to quit, so I’d like to know how long I’m going to experience strong withdrawal symptoms. The worst fears I have about quitting is depression and irritability…How bad is it going to be?

I workout and have a healthy diet…I don’t know if that would be a factor.

Also, what are some ways to curb those symptoms?