First, maybe think about changing your thinking about "being good" and being bad. If you are eating lightly all day, you are probably hungry when you go to work, so its natural you'd be hungry. Make a plan for a full day's meals - planning out breakfast, lunch and dinner. You could even incorporate some of the fried food into your plan if you know you will eat it anyway.
Can you clean while you are at work to keep you busy? Or do leg lifts while you stand there?
It's about commitment, not motivation.