Firstly STOP!
Your diet won't fail because you had an off day. EVERYONE, no matter how much they want to be slim will have those days where, despite the best of intentions, you go off the rails and have things you feel you shouldn't. The difference between the odd day ruining your weight loss efforts or just being a blip, is YOU! So you fell off the healthy eating wagon for an evening......its just one evening. If you beat yourself up about it you'll be more and more inclined to believe that you can't do it, that you can't stick to it, and so therefore whats the point - you give up, you have day after day of eating junk and before you know it you're ballooning up and wondering what the hell happened.
DRAW A LINE - You had an evening where you enjoyed chocolate, crisps, wine.........and so you should have enjoyed it - DON'T feel ashamed or guilty. Say to yourself that it doesn't matter and get back to the healthy stuff. If you continue to allow yourself to feel bad and deflated about it, it won't just be a blip.
As for the fact that you've been sticking to plan and the weight isn't shifting. I find if i have too many green days or too many carbs my weight loss slows down or stops entirely - so maybe a few more reds may help? Also drink LOADS of water.
Anyway hun, we're all here for you. It was a blip - nothing more. And although you may not be losing the pounds think how much healthier you are eating all the fruit and veg, how much less of a strain you're putting on your body, how much better your skin looks......there are so many more positives to this eating habit than 'just' the weight loss. xxxxxxxxxxxxxxxxxxxxxx