Cheryl! And congrats on your loss!
I usually avoid cravings by allowing myself to have a controlled amount of the thing I crave in a controlled situation. For example, I have a weekly "cheat" meal where I am allowed to eat whatever I want. Then when I'm craving ice cream on Wednesday, I can talk myself out of it by saying, "Well, I can have ice cream on Saturday for a cheat meal. I can wait a few days for the ice cream, it will taste just as good then." Often by the time the weekend rolls around I don't have the craving anymore.
I also avoid having things I crave in my house. If I really want ice cream and I decide that I am going to have it for a scheduled treat, I will go out and buy a single scoop of ice cream. If I do that, I can't eat more than one scoop, whereas if I bought a half gallon to bring home I would eat much more of it.
So I guess what I'm saying is that it's true 1 treat doesn't matter in the grand scheme of things, but you have to make sure that 1 treat doesn't happen too frequently in order for that to be true. I like the idea of scheduling treats because it gives me something to look forward to, gives me willpower to avoid treats on other days, and avoids guilt because technically I'm not going "off plan" when I do it since treats are part of my plan.