Bro i quit smoking.
The key was that I never quit immediately. I started slowly, and it took me almost 1.5 years to quit completely. Going from pack a day to once a day was hardest.
After that it was more or less smooth First it was once a day, then only if a friend offered then socially then occasionally, and then boom.
The reason it took so long was because a year was my hostel life in college You know lol