What is your diet like? If it's too restrictive it's bound to cause cheating and binges. Your have to make sure it's a balanced diet. You can survive without sugar however you do have to have some protein and keep your blood sugar levels even in order to feel sane. Without knowing what your diet is its impossible to know if it's even appropriate to say "you can do it!" Because some diets can be ridiculous.
Fat isn't a feeling
"Food is not the enemy. Hunger is a sign of life and vitality." - Caroline Haagen from The F- it Diet