My Stomach Hurts Last Night?

All I eat yesterday was a bowl of rice, 3 bottles of water, and 2 pieces of chocolate. I don't know why, but around 3am in the morning, I woke having terrible stomachaches. I could feel my forehead sweating, but my forehead was extremely cold. And I was just so weak, I could bare stand up, and my stomach was in pain. I crawl down stairs, layed on the kitchen floor trying to open a bottle of painkillers. It's still on the floor lol, but anyways, I took one and just clenched my stomach till I feel asleep. Do you think it was because I didn't eat enough? Because I honestly thought it was good amount...