Wow...get rid of the Spongebob Squarepants cereal. For real. Cereal with marshmallows of any kind does not constitute cereal that is appropriate for a healthy diet.
You should be eating cereal with fiber--LOTS of fiber, if you can stand it. I eat Nature's Path Optimum Slim, with a whopping 11g of fiber.
And there's no need to go low-carb, but seriously, Shauk--eat some whole grains! There are no whole grains in your diet! Fiber, fiber, fiber--lots of whole grains, lots of fruits and vegetables. Apples and bananas are portable. Clif Bars are portable. A bag of salad makes an easy lunch or dinner.
More info on the health benefits of fiber:
http://www.hsph.harvard.edu/nutritionsource/fiber.html
Fitday.com has a great diet tracker that I think could really help you set some goals and maintain them. You should be aiming for at least 30g-38g of fiber a day.