Worried about what i ate-and what i will!?

so, tonight i didnt plan to eat 5 piece of pizza but i did. i am going on vaca for two days to ski which means a lot of unhealthy eating-tomorrow and tuesday, big dinners out, eating the huge irresistable waffles they have there, and little things on the way up like starbucks and DD. i ran this morning and last morning for an hour but will not be able to tomorrow before we leave at noon because it will be snowing. i wish i didnt eat the 5 piece of pizza because if i didnt i wouldnt be worrie about 2 pig out days without running, but now that i ate majorly unhealthy the day before by eating 5 pieces of pizza- i am worrie it will all add up. im not asking for workouts or anything, im just very worried. i feel as if even if i eat a small candy i already see a difference in my stomach gettig bigger, i dont know why my body is like that. but now that ii had all that, and am going to have much more for two days in a row, im going to get huge. im nervous. an upset with myself.