Well done on three weeks mate that's a great effort. Don't worry about going out but do you have a plan? What are you going to say if anyone offers you a drink? What if you feel tempted? I think you should go prepared.you could just say you don't drink and don't make a big deal out of it.in my experience WE make more of an issue out of not drinking than the people we are with. Most people don't care whether we drink or not they really don't. So go out have a great time and be the cool and interesting one who doesn't drink!