Could this be diabetes?

I'm 18 years old, female, 115 lbs and 5'1", and for the past 4 or 5 years I've had a constant hunger and thirst it seems, but for the past year it's been progressively getting worse. And although I eat so much, often more than my parents even, I never gain any weight and always feel tired. Even only an hour after eating a large meal, I feel as if I haven't eaten in days and the hunger pains get to be really annoying. Although when I fulfill my hunger, I get stomach pains/cramps that feel almost as bad as the hunger pains did. For example, a few days ago I ate lunch at school and then went to my class right after lunch, and my stomach was growling very loudly throughout class even though I had just eaten a lot for lunch! And the other day, I ate a big bowl of cereal for breakfast, then ate a large lunch, then ate 2 peanut butter and jelly sandwiches as soon as I got home but still felt like I was starving, then had a big plate of spaghetti and 2 pieces of garlic bread, then had a snack afterwards because I was still desperately hungry. Im also constantly thirsty and sometimes upset my parents because of how quickly I go through every beverage in the house. I'm getting really sick of this and have made an appointment with my doctor but they couldn't get me in until may 17 so I just want to get a few opinions to ease my mind and figure out what's wrong with me.