Your breakfast is making your hungry rather than keeping you full. You need to add some good protein to this, personally everything in the cereal aisle is processed food that should be eaten for dessert, that's how much sugar it has in it. I would rather skip breakfast all together than eat cereal... I guarantee you that you will be less hungry at lunch time if you skip it. As a matter of fact, some people who practice intermittent fasting do skip breakfast every day and they're fine.
I do eat breakfast, but it has to be full of protein and just a little bit of carbs. I like to throw in veggies right off the bat so I'm most likely to scramble a couple of eggs with spinach and cheese and a slice of whole wheat toast. If I eat this at 9am I can go until 2 or 3 pm without even thinking about lunch.
"No matter how developed you are in any other area of your life, no matter what you say you believe, no matter how sophisticated or enlightened you think you are, how you eat tells all." - Geneen Roth