I'd recommend going to AA meetings. AA has a vibrant network of people dedicated to not drinking meeting everyday all around the world. If you don't like the first meeting try a different one, they vary widely.
Find other indulgent drinks to enjoy, ginger beer is a fun one that is widely available.
Tell friends you "don't drink" once, if they need to be told more than once they aren't your friend.
Much of the physiological drive to drink is literally based on thirst, so keep yourself super hydrated at all times. Being hydrated also dilutes your stress hormone (cortisol).
Exercise more, if you stop chronic drinking provided you're otherwise healthy you should start to feel much more energetic in a few weeks. Use that energy to improve your body and mind with rigorous exercise. This will help you look better, feel better about yourself and gives you a reason not to drink. A hard workout gives a feeling really similar to drinking but entirely healthy and natural. The more you look like a serious fit athlete the more people will easily accept it when you pass on drinks.
Crossfit gyms are a great place to make friends with healthier people.
Good luck!