Why am I always thirsty

lately I've been drinking around 64 ounces of water im 18 and 107 pounds the problem is that I drink and drink but my thirst is never quenched also right after I drink water I urinate no lie 10 minutes after I drink. And it's not just once I pee nonstop for the next hour and I feel like the urge doesn't stop it doesn't hurt I just pee like there's no tomorrow.. Anyway my throat feels dry and it hurts to swallow .. Does anyone know what's wrong with me I'm getting pretty worried...