Well thats exactly what happened to me, the onset of a bunch of those very same symptoms fairly quickly. Im really surprised your doctor didn't do a simple finger stick as well as the "take the blood from your arm" test. The finger stick probably would have told you a lot by the number. I walked in and they nurse did a finger stick and the number was "350" and the doctor said, "yes, you have diabetes!". With that number and the classic symptoms which both you and I had, it was pretty obvious.
If you really want to know, find someone with a testing kit and do a finger stick and test your blood. Try to do it at least 2-3 hours after you eat so you don't get an abnormally high number based on a meal. I'll just bet you are going to run somewhere over 150 and that will put you in the "I need meds" range.
Thank you so much everyone for your views and advice... means a lot to see there are people who can recognise symptoms and also give reassurance that it may not be what I fear after all - though best not taking risks - just in case. Thank you all so much and I will most certainly let you know what comes of the tests. If it is diabetes god only knows I will be asking you all sorts of things to guide me through - based on people who have actually got this as well as taking the advice from my doctor.