Ah.... I see you are 17 yrs old,so its likely they may have caught you in the early stages,although they say that sometimes people have Diabetes for 5 years prior to diagnosis.
This is usually Type 2 though as that is uaually more gradual,but you may have noticed symptoms for a while,and not realised their significance.
I would agree with madcol,try to lose weight,if you can,as this will help you "control" this.
Reduce the amount of Bread,Potatoe,Rice or Pasta that you eat,even if its by 1 Tablespoon.
Try to exercise more,even if its just a walk round the block each evening,try to walk fast enough to make you out of breath,this alone will help reduce your weight,and exercise can lower your blood sugar.
Dont worry too much about this,as gradually if you are Diabetic,you will come to understand the information you are given about it,and make changes in your lifestyle which will help you control this condition,so that you live your life normally,and without too many restrictions.