I can't dose for cereal either, and it's one of the foods I really miss since DX a few years ago. I used to love having a bowl in the evening as a before bed snack.
I have found though, that certain cereals are easier than other. Frosted flakes, raisin bran and a few others are all really rough. As the box says they are "high in fiber" yet have 50+ carbs for 3/4 of a cup and are REALLY high on the glycemic index.
On the other hand, my Count Chocula (marshmallows and all) has 19g of carbs for a cup. Even though it also hits quickly, if I'm at say, 70, take my bolus 20 minutes of so before hand (that way my insulin hits whil the food is spiking) I don't have too great of a spike for it.
Also, I agree with the people here saying it could be mind over matter. The first time I ever started to really loose it from a hypo was in the shower. Now I have a mild panic attack almost any time I set foot in one....