I had the same problem the last time I tried to lose weight, I'd buy a container of Skinny Cow ice cream sandwiches, and eat most of them the same night. I'd start out by planning them into my calories for the day, but as soon as I finished one I started obsessing about the next one... and a binge would start. And like Marms said, it was never satisfying, I always had to have "real" food anyhow.
So this time around I don't really eat any "diet" food. I eat normal cereal or oatmeal for breakfast, normal sandwiches or salads for lunch, and things like baked potatoes, soups, and pastas for dinner. I don't have anything that's been altered to be low-cal or low-fat. On rare occasions when I snack, I usually have a piece of fruit. I find it's working great for me, and I'm much happier and more satisfied eating well-chosen, reasonably-portioned regular food.
Edit to say, btw, that I do still eat "treats", frequently, in fact! Just yesterday I had a real, honest-to-goodness chocolate chip cookie from the bakery across the street, and today I had a real PB&J sandwich! Plus my daily multivitamins are
delicious jelly beans.

So by all means, have "treats"! Just plan for them, and make sure they're going to leave you feeling satisfied and happy when you're done, instead of empty-feeling and miserable.