Sometimes falling off the wagon means that the diet you're following is not for you. The rule of thumb in these things is that you need to push through for about 3 weeks to get your body used to it. If you still have major cravings after that, it means that something is missing. (What you crave is usually not what you're missing. It's a guessing game sometimes.) Maybe if you share what are your cravings/body type/major symptoms someone might have an idea which kind of diet could possibly be good for you?