Is it possible to have diabetes at 15 years old?

I am 15 years old and my mom's friend told me that I may have diabetes. I looked it up and I seem to have a few of the symptoms. I am always thirsty and I mean ALWAYS. I try to drink water as often as I can, but it never satisfies me. I always want Capri Sun or Koolaid or something with lots of sugar in it. Even then I still want more to drink. I have frequent urination. I bruise very easily and they stay forever. And when I get a cut, it takes forever to heal up, and even if it's just little it will most likely scar. A lot of the time when I'm playing my guitar, my hands go numb and lose feeling, and my guitar instructor says that this is abnormal. And at night I am starving. I am never hungry during the day, but at night I have to eat or I will go insane. And I have really dry skin (although I have always had really dry skin on the back of my arms.) And I always shake really badly and my legs are really jumpy, and I always have to chew gum or something. If I don't I get headaches. Could I have diabetes? I'm not overweight, or extremely unhealthy.My great grandfather had diabetes but no one in my immediate family does. Should I see a doctor about this? Help? :P