Generally, i think the onset of type 1 is fairly quick... 2-3months. As with type 1 the insulin production stops and so the blood sugars go up quickly.
If you're levels fasting are at 7, then that is a little higher than it should be. Im not so sure that 7 would cause your excessive thirst, increased visits to the loo and blurry vision though, having said that everybody is different!
It's well worth your while going to a pharmacy and buying a blood glucose meter, like a OneTouch Ultraeasy or a freestyle... they dont cost much. Anyway, once you have on of these you can test your blood sugars yourself.
I suggest you test once when you wake up... which is a good fasting time. before you eat and 2 hours after a meal (no less 2 hours). all of those results *should* be with 4 - 7mmol/L.
If they are all higher... particularly the fasting result, then go back to your doctor WITH your readings. If he doesn't listen then see a different doctor.
Good luck!