Diabetes help?

[Frannie]

I am starting to get worried about myself getting diabetes, but the symptoms could be found in anything. Maybe if you know anything you can help. I have 2 grandparents with type one and another grandparent with type two, my uncle was diagnosted with type two recently, and my dad is starting to show the same sighns my uncle showed though he had not been testing yet. But for the past several months I have been extremely thirsty, I drink a gallon or more of distilled water a day, no exageration. My vision has always been pretty bad, but since this June my perscription had to be changed once about two months later, which my doc said wasnt good cus it looked like they had stabled out in june. Im Catholic so for Lent this year I gave up sugary foods, and since then Ive felt like I was gonna passout at several times, like this odd dizziness, since i havent been drinking my soda everymorning like i used to. And when i do experience those "lows" i have the worst feeling like im gonna be sick
and this pain in the middle sides of my abdomen. i have drinken a bunch of juice once when i felt like this at the advice of a teacher and after about half an hour later i felt better for a while. Is it in my head or should I get checked asap?
ive been checked about a year ago and i was fine, but i dont know, im a bit worried. thanks
I would like to say thanks to everyone who has helped.
Also I would like to add that Im 17, 5'1" and weigh 86 pounds, and I eat like a horse, I can not seem to keep weight even when my doctor put me on weight gain protien stuff...but that could be from my heigh metabolism.