I had loads of days like that last month. If you can, draw a line under it, and don't let 4 days become an excuse for it to drag on to a week or a month. Just because you've eaten some junk already doesn't mean you need to eat more. If you can, get back on the packs, or maybe do working solution for a bit if you want to eat some food.
As Coley says, if you can identify what's triggered it, it may be good to have a plan for how you would handle it differently next time.
My current secret weapon is a peperami that lives in the fridge, and is a lot less off the wagon for me than the other things I was jumping to last month!
Good luck, and remember your goal and what you're trying to achieve.