Be realistic about your diet, and allow for sweets
You will be more successful when changing your diet to be realistic about what foods you will eat and what foods you will avoid.
Try observing what you eat, how, and why, for a week. Some people overeat when sad, mad, or happy. For example, myself, I tend to overeat when I am bored.
Knowing what triggers, you to overeat or eat foods that are not good for you, is important.