Bah! No worries. What's done is done and it looks like you're already in damage control mode. A little treat once in a while is not what made us fat, it's lots of big treats allllll the time right?
Bookmark your post for next time you feel like slipping! A little reminder of how you felt this time might help you for next time.
I usually have a little "treat" planned sometimes during the week, but if something comes up and I end up having an unplanned treat, I just pass my planned one to make up for it. I have to say, planned treats just taste better for some reason.