hello i am 21 years old, i am around five foot eight and a half. and i think im about nine and a half stone. I have polycystic ovaries and the doctors tried to test my blood sugar levels i had to fast and then they took a blood test, but my blood was really hard to get and they only got a little bit then i fainted so they could not test my sugar levels as they didnt get enough blood, i want to get tested again to find out if im diabetic but i dont want to faint again, i also get regular dizziness and like slight blackouts when i stand up sometimes. what do you think i should do?