What can I do to stop smoking I will stop then I will crave if again and I don't why I smoke what can I do.?

Stop smoking. Nicotine addiction is a tough problem. First be aware of health consequences of yourself and everyone around you. Set a quit smoking date, start cutting back gradually, tell everyone you are quitting smoking on that date, and tell them why it’s important to quit smoking. Get everyone’s support. Consider joining a support group and talking to a doctor about medications to help you stop if necessary.
Craving. Stick the right dose of nicotine patch on your back, and the craving will stop because the brain has the right amount of nicotine. Tell your doctor how many sticks you smoke daily to help inform the right dose of nicotine patch. Get some baby carrots and load them in your container, pull one, light it, then smoke and chew it for a couple of minutes. The rituals help stop craving too!
Cold turkey. As far as quitting without any nicotine replacement, the cold turkey method is great. But plan it ahead of time. Pick a quit date in advance, maybe a meaningful date like a birthday or holiday, and gather people who are aware of your attempt that you can call upon for moral support if you start to falter. Good luck!!