I'm a super logical person so when something like this happens to me I try to be as rational as possible. First, you likely ate over your deficit calories today, so today won't contribute to your weight loss. That leaves two scenarios. It's possible you ate around maintenance, so it could be a 'wash' as far as gaining or losing. It's also possible you ate over your calories, but unlikely no more than 1000 or so, which is way below what it takes to even gain a POUND. < one tiny pound. In either scenario, you are not in a terrible dark hole of weight gain where all that hard work you've put in the last few months is for nothing.
So, the way I see it, you're okay. You didn't do what you wanted to today but that doesn't mean the rest of this evening and tomorrow and the next day aren't great opportunities to make better decisions every single minute. Maybe go for an extra walk tomorrow and eat really clean- by treating your body kindly you'll feel much better about yourself physically and emotionally.
I hate days like this...
