Hello finebutnotokay, I wonder if you can get to a point of feeling proud about not drinking rather than feeling bad about it. A friend of mine does not drink simply because his best friend only has one kidney so he doesn't drink out of respect for his friend. There are many things you can say if you feel you need to justify it. You could say that you can have a good time without it so you don't need it. That often makes others think about their own drinking habits a little more. Or if you feel you have to say something, you can just say it is for health reasons.