I used to be the same way. I had issues with cereal, but also grains. Luckily, I am in a smaller household, and no one here has cereal. I started low carb at 350 + lbs, so i was too lazy to go out to get it, so the only need for willpower was when I was shopping...lol.
Not sure if it is addiction, or just trigger foods causing intense cravings, but for me, I couldn't eat enough. It might be a box of Cocoa Krispies, but Fiber One cereal had the same effect on me. We are all different. Many people thrive on carbs, but a small percentage don't.
I stick to low glycemic vegetables now, for the most part ( around 10 servings ), and the rest is chicken, eggs, butter, oil, nuts, and cheese.
Whatever the reason, you need to find a way to go 3-4 weeks without eating the foods that cause cravings/addiction to break the cycle. If I said to smoke crack slower, so you did less, we would all laugh, but when it comes to food, we tend to think moderation will solve the problem. For someone who hasn't experienced your problem, they tend to think that you are just overeating, and eating slower would make you feel full with less food.
If you are eating a box of cereal at a setting, and still " hungry ", this isn't hunger though. You may be eating till you hurt, but still want more. It has nothing to do with willpower, as you know. I never overeat protein, or fat. It is always carbs, so I avoid the ones that cause these cravings.. bread, pasta, cereal, corn, and potatoes for example.
I would suggest that you read some books at the library.. some low carb diet books, as well as low glycemic books, and decide if either would be beneficial to you. Sometimes just changing the types of carbs we eat does the trick. If not, you may need to eat less carbs to regain control. Read up, and work out a plan with your doctor or dietitian that works for you.