I gave up and dropped the 2 stone almost instantly, and it stayed off.
My advice, don't worry what others think. Drink soft drinks and be up front about it. If people ask why you don't drink tell the truth. Its nothing to be ashamed of.
You'll find that drinking soft drinks get you out of 'the round' too, where the drinkers will happilly get you one too as its only a soft drink. I go out for the night and I drive but in return for picking up and dropping off, I don't spend a penny!