I have little blips here and there but find that I can put brackets around them and move on by challenging my thinking - a blip isn't the end of the diet, it isn't the end of dieting for the day, it is just that - a blip.
I find that by challenging the negative thoughts (ie, I have failed, I can't do this, I am rubbish, etc) and replacing them with positives - look how much I have lost, it isn't the end of the world, think how much I would have eaten before I start LL, etc, I can put the blips into their rightful place before the crooked thinking takes over and a blip turns into a disaster.
You are doing brilliantly, put this to one side and carry on.