Hang on!! You're going to get past the cake. You're right to not let one mistake turn into TWO, then maybe three when the crash happens after the cake and you find yourself thinking some pasta would be good, since you already had the cake... I find myself all but beating myself over the head with my Dr Phil book to keep from the "all or nothing" thinking that leads me down the "I've already blown it, so I might as well make a day of it! I know for me, that can easily lead to "I've blown it today..might as well have the weekend off..."

You can do it!