The weight loss process is not without its ups and downs, as you might well know. One of the downs occurs quite frequently when you fail. Failing to live up to your promises. Failing to live up to your expectations. There is even failing to do what you are supposed to do. If you have your mind set on losing unwanted weight, you will have to deal effectively with failure.
Can you say to yourself that you still believe you can do what it takes to lose weight after you fail? If so, and if you are sincere about believing in yourself still, then you are way ahead of the curve.