Sugar

I think it's a better idea to ask this question to a doctor instead of us.

could be a number of things... is your medicine working?
what did you eat? hey keeping a diary?

talk to the doc? does the doc seem to care or know what they're talking about?

does it happen when you drink water, where did the water come from?

did any exercise or strenuous activity...?

and so on.

check your blood sugars, right away.
THat's actually -always- the answer for a diabetic, for anything out of the ordinary, but for me, moodiness & headaches usually come with high blood sugars

not good at all , eating too much sugar can cause cavity on your teeths

Do you test your glucose regularly ? Are you seeing peaks when your blood sugar's really low or really high ?