I totally feel your pain. I know there are a few of us on here that prefer to "stay in our box" because it's comfortable and we aren't tempted.
I have the hardest time when I'm travelling. It's not that I don't KNOW what choices to make but temptation just gets the best of me.
First of all, I would say avoid buffets. Those are ridiculously hard to control yourself at.... especially because most people feel like they need to get their moneys worth.
Try to plan. I typically do better if I know WHERE I am going to eat and am able to look at the menu online. That way you can look up calories (if you're on WW or calorie counter). Also you go in knowing what you're going to eat and you aren't overwhelmed by the choices or tempted by whoever you're eating with.
Don't feel bad - I think all of us have been where you are. I just had 3 weekends like that, but I'm back on the horse, just like you will be too. The important thing to remember is just because you have a few horrible meals doesn't mean you need to continue to make bad choices. You don't have to continue to "damage" yourself. It may take a week to balance yourself back out, but you can do this.
This is why we're here.... to support each other.