As strange as it sounds, and I've told this to a few others, even making small changes will make a difference.
For instance, if you have to have a snack, try to make it just a little bit healthier (veggie chips instead of the fried potato chips, maybe). If you have to have candy, have a small piece instead of a whole candy bar, etc. If I've got to have SOMETHING for ME during the day, it'll usually be a hot cup of coffee instead of that sugar filled latte or whatever. If I've got a craving and I have to have something, I try to make it a smaller portion.
I did WW for a good while, and the focus at first was not so much portion (fresh fruits and vegetables, anyway), as eating healthier in general, and then focusing more on portion.
We all still have our bad days, but just focusing on "better" choices is a good start.
"A Dog is the only thing that loves you more than he loves himself"