Scrapping it and starting over

During this year I have been fighting to get rid of the last 10-20 pounds, getting those lean and strong muscles. I am on a roll, being very proud, boyfriend egging me on. Feeling great, then something interrupts my plan, a big meal out with work, someones birthday, cake all around and I feel as if I have fallen completely off the wagon, usually i just saw, screw it and just stuff my face and tell myself I deserve a treat. (which you do once in a while, I just need to choose my rewards more carefully) But this year I am saying NO to complete failure, if it where to happen that I fall off with a big caloric meal, start the next day already with a workout, it will make you feel 1000 times better and we don't always have the feeling that we are starting from scratch!