Cindy,
I have the exact same weak periods. At 10:30, I usually just try to hold off until 11:15, at which point I beging making myself lunch. I can do that since I'm at home. If I'm not at home, like yesterday, I make sure I have a healthy snack with me, and have that. The 2:30 time is much harder for me, because I'm also dragging my butt by then. Usually I have a huge glass of water, followed by a cup of tea. (used to be coffee, but the health benefits of tea convinced me to go that route) Usually works, but again, keeping a supply of healthy snacks is key for me. (I used to eat bread whenever I got hungry!

) You may want to think about having more protien in your snacks. The things you are having are mostly carbs, and I'm sure you know that while they work short term, they don't carry you very far. Try some nuts, or protien bars. (Be careful of these bars though. Some are no better than candy. Try the Pria bars. They are high in protien, and not loaded with sugar and unneccesary calories. Lot's of times you can get these relatively inexpensively at warehousr clubs, like Sam's and Costco.)
Also, think about wht you are having for breakfast. I used to eat cereals llike granola and Special K. I have since gone for more protien and bran and found that carries me much farthter through the day. Same thing with lunch. Try to get a good source of protien. Remember, not all protien foods have to be fatty. Go for soy based things. I really hated them in the beginning, but like anything else, I got use to, and eventually quite fond of them. One staple that I always try to keep with me are Odwalla Super Protien bars. Very low fat, (5g total, 1g. sat,) and 16 g. protien, and 240 calories. That is a lot of calories, but not for the amount of protien. I also have it with a glass of skim milk and call it a meal. It usually fills me up to the degree that I may only need a piece of fruit to hold me over.
Sorry so long, just some Ideas.
Keep the Faith!
Tracy