Terri,
First of all, don't even bring junk into your house. From looking at your plan, it doesn't appear that you are eating enough protein which help fills you up. If you are eating every 2-3 hours and hungry at the time of your next snack/meal, then maybe you aren't eating enough in general. Perhaps add extra veggies and add some protein at every snack.
Also, I'd look for extra sugars in the things you are eating which can actually make you hungry as well. The whole grain cereal as well as the peanut butter could have sugar added to it. I am a pretty severe label reader and you'd be amazed how much things are added to our foods that aren't needed.
Also, not sure what type of yogurt you are eating but the best yogurt I've ever had is a sugar free/non fat yogurt, yoplait with the blue lids. They have real fruit in their fruit yogurts which I like. Although I'll admit the only yogurt I eat is nonfat plain, quite boring
For breakfast this morning, I ate some low fat cottage cheese, mixed with some nonfat plain yogurt and splenda.
