What Causes Stomach Cramps,dizziness And Headache?

Hi, I have a really bad stomach ache, I'm cramping up a lot, I have dizziness, light headedness, I'm extremly hot and I'm in a freezing cold house. Also I went to the bathroom twice and the first time there was a little blood and the second time it was pretty all blood. I have a horrible headache also. It all just started about 30 minutes ago. I'm a 20 year old male. I need to really figure this out...