If you're on-plan, and your plan works for you, it WILL work. Sometimes it works over a month rather than over a week. I know I often have to look at the overall trend rather than the day-to-day (or even week by week) or I can get discouraged.
I also write up "health scripts" -- encouraging pep-talk paragraphs and motivational sayings that help keep me on track -- and re-read them when I need them most.
If you can hold steady for the evening, chances are good you'll be okay tomorrow. Studies of dieters show that if they stray in the afternoon, and "give up" for the evening, they may get completely off track. If on the other hand you stray in the afternoon, and get right back on-plan the rest of the evening, you are less likely to get off-track more than that.
And for future, you may want to look into tools for helping when this happens again (and it WILL happen again -- it happens to all of us!). Plan now for that eventuality.
Most diet plans are great for telling you what to eat and what not to, and what exercise to do. They don't really touch on how to deal with food you have a "history" with, binge-triggers, family issues, social food situations, and how to recover when you stumble so you don't just throw yourself down the mountain instead.
There are a couple of good books that deal not just with diet, but with behavior change. You might find them in the library. My go-to books for this sort of thing are Four Day Win, Thin Commandments, and Beck Diet Solution.
You CAN do this! And next time, the good habit will be that much stronger.
~~ Synger ~~