Nefarious, I think others have said this, too, but you need to eat both protein
and veggies, like you did at lunch. The veggies fill you up and the protein keeps you full longer. One or the other and you don't get what you need. The nuts make you full longer, but they don't fill you up much. The celery fills you up a lot, but it doesn't last very long. Put them together!
Also, try eating something a little earlier in the day, possibly. If you spread your eating out more, your body will have more time to process it.
You also might benefit from another serving of beans, peppers, or tomatoes...those good carbs can help stave off cravings in Phase 1 also.
Drink more water. It helps fill you up, keeps you from munching on other things, and sometimes you think you're hungry but you're actually thirsty!