Help I stopped smoking for 14 days, and then met up with a friend and had some cigarettes,

All is not lost. We learn from mistakes and this is no exception. You are learning about yourself, your strengths and weaknesses. You will succeed if you try and try again. You will never win if you do not. Each attempt brings you closer to your goal. Every day without the toxins, your body gets stronger. Each time you win against a craving your mind gets stronger. As you are rewarded the benefits of quitting smoking you will want to hang on to them. Your self confidence will build and you will be a winner. Keep at it. Stay positive!