I never smoked, but I was addicted to sugar. The way I see it, an addiction is an addiction.
The way I got over my addiction, was every day when I'd wake up, I'd remind myself that today's goal is to live a healthy lifestyle. There were days by noon time, I was craving a soda, candy bar, anything. I'd need to keep reminding myself that today's goal is to live a healthy lifestyle.
I kept my focus to one day at a time. Before I knew it, one day turned into a week, which then turned into several weeks, which then turned into a month. Even after a month, I was still craving sugar. I felt since I was a month in, I couldn't turn back now.
Before I knew it, I hit the 5 month mark...and I no longer craved sugar.
What I went through wasn't easy...I sympathize with people trying to quit smoking. I really believe if your focus is a healthy lifestyle, you'll be able to quit without using substitutions.