What's up with my metabolism?

Okay, so I was eating normal last week, and staying normal weight. But yesterday, out of the blue, I just got seriously hungry and would not stop eating. I kept eating a ton of fruit and I couldn't stop drinking OJ, and it wasn't normal hunger, it was like painful hunger pangs that would not go away the entire day. I eventually stopped eating, but the hunger was still there. I went to sleep and when I weighed myself I'd lost two pounds since yesterday. What the hell? Usually when I eat a lot I don't get thinner...and I normally don't get hungry.