Your diet sounds kind of unhealthy, to be honest.
Maybe you need to eat more filling meals so that you don't feel the need to snack?
I'm thinking breakfast with a mix of carbs and protein, such as toast and egg, or beans on toast;
then include some low-fat or "healthy fat" protein food at lunch (nuts, tuna/oily fish, beans, mushrooms, etc);
and including plenty of vegetables with your dinner - which should be a full, balanced meal - just not too large on portion size.
Try that, and see how you go.