How can I stop smoking when everyone around me smokes?

Try distancing yourself from that, you have the choose to stay or go. It's up to you to surround your self with those things.

Determination

Think about how bad it is and try to be the better person out of all those people when you see them smoke. It will be hard but you have to try you can do it. Try to eliminate some of the people who smoke the most around you. Try and get those people out of your life as much or just quit hanging out with them as much or at all. If you still can’t stop maybe try some online methods or some counseling or meetings. I know it can be hard but I know you can do it.