sweet tooth

I sure am not a healthy person based on what i eat. I don't eat veggies that much but i eat a lot of junks. I could munch this pack of chocolates in one setting. I eat a lot of stuff from food chains and i don't exercise. Whew! no wonder i'm gaining that much! I know i should be changing my eating habits. But what can i do? I have a sweet tooth i eat anything chocolate and sweet.