I'm just going to echo Lovely's advice here- to lose weight, you don't have to be perfect, but you do have to keep going! I read something the other day- I think it was actually in an interview with Jillian Michaels- and she was talking about this same thing. She said (about having off-plan indulgences), "it's like if you get a flat tire. You don't get out of the car and slash the other 3! You change the tire and move on."
Reading that made me chuckle because I used to be such a tire-slasher dieter. Big time. I'd eat one thing off-plan and in my mind it was all over and I'd eat 10 things off-plan. It's taken me a while to learn that one mistake does not mean I have derailed the entirety of my weight loss journey (or that I should go ahead and run it right off the tracks). You pick yourself up, you move on, you plan on doing better at your next meal.
"Blessed are the curious, for they shall have adventures" -Lovelle Drachman