I was diagnosed with diabetes at 8. Symptoms to watch for are the symptoms of high blood sugar:
frequent urination, drinking large quantities, losing weight, tiredness, and in extreme cases, shortness of breath and chest pains (don't worry too much about that unless it happens. i think it's quite unlikely in a new diabetic). testing for diabetes is very very easy. all it takes is a drop of blood.
I'm not seeing those symptoms, just the headaches and vomiting. Thanks for the info.