I was in exactly your situation a few weeks ago, and it turned out that I have Type 2. I can reassure you that things really aren't that bad! A nuisance, yes, but not a disaster. Although your symptoms could be caused by many things, given your family history it is quite likely that you do have diabetes. If you do then the important thing is to get it under control as soon as possible. This disease is completely manageable - especially if you get it diagnosed at an early stage. You will also find that once it is under control you will feel a lot better (I didn't realise how tired and run down I had been feeling until I started to feel better).
What will happen at your doctors is that you will initially be given a simple blood test, and possibly a urine test (it would probably be worth being prepared and taking a sample along to the appointment). If either of these show raised levels of blood sugar then you will be given a glucose tolerance test (which is how diabetes is diagnosed). This involves you being starved overnight, then having a blood sample taken after which you are fed a glucose drink (lucozade or something similar). After two hours a second blood sample is taken. These samples are then compared in a lab to see how your body copes with the glucose - and from that a doctor can tell whether or not it is diabetes.
If you do indeed have diabetes (remember that other things could cause your symptoms), then depending upon what type it is and how advanced it is your doctor might want to put you on drugs or insulin. However, if it is Type 2 then it is quite likely that you would be encouraged to try controlling it by diet alone initially. In any case you should be assigned a specialist diabetes nurse, who will advise you on your lifestyle, and you might be referred to a specialist diabetes doctor. If you are diabetic then the most important thing is to not panic, but rather learn all about the condition that you can. There are various useful books, and this discussion forum is a great community of people who can offer you lots of advice. If you understand the disease then you will find that controlling it isn't too hard - but knowledge is the key.
will this go away as soon as I am diagnosed and then treated? It's rather annoying, especially when I have a 3 hour class (I'm a student). I'm a little scared and I need some reassurance from people who have been in my shoes before...