Hi Charlotte,
and welcome aboard a very select bandwagon. All those type 2's like to pretend they're diabetics, but they're not foolin anyone, are they? We're called type 1 for a reason!
As for the cereal issue, there is no insulin on the market which will cope with the sugar rush that cereal and fruit will deliver to your bloodstream. You are injecting enough to bring your blood sugar down from 22-24 (aaargh!) to 7 (still too high) so that's probably quite a large dose, but as you can see, it's fighting an unwinnable battle with the sugar.
A word to the wise, though, don't start using more insulin. That way madness lies. Try eating less starch instead. What else do you fancy for breakfast?
All the best,
fergus