As Tracy said, you can still go out and have a social life, you just need to make the right choices. If you deprive yourself too much you will go straight back to it once your "diet" finishes. Life your life the same way you have done, but have a vodka and soda water & lime or diet coke rather than whatever other booze you drink, when ordering food, if you cant go for the healthy option...have less of the fattening one (don't finish the full plate) if you cant manage that then do extra exercise for the next couple of days. It really isn't as hard as it seems!!
Good luck & enjoy life, being healthy shouldn't stop you enjoying life
xxxxxx