Yup, I feel exactly the same way! I'm a (relatively) new diabetic and have been limiting carbs for the first time and very closely watching my 2-hr post meal blood sugars. If I eat enough to make me feel full I really sweat it out during those two hours, thinking that I've totally blown it. *Very* guilty feeling, bleh.
Funny thing is, my blood sugars are always fine at those moments. It's when I think I've done well that they can surprise me.