How to contain my self from eating too much sugar? Help!!!?

I usually eat 1 or 2 sugary snacks everyday and I feel guilty. Sometimes even if I see like a bag of cookies I go eat a few. It’s so hard to help it! I just love snacks but I really don’t want to get diabetes. I want to live a long healthy life. Sometimes I even overeat. But I do drink a lot of water each day, 1 glass of milk everyday, I always eat fruits each day (I eat fruits like blueberries, raspberries, cherries, bananas, sometimes oranges, strawberries and grapes) I even eat 3 prunes every night . I do not drink juice or any other sugary drinks. I do exercise and walk almost everyday.