Why did I get sick yesterday?

Well yesterday I was in PE and we were running laps. When I finished my second lap I was really out of breath but that was normal. But it didn't go away, usually about 1 minute later I was normal again but I was still really out of breath. My lungs started to hurt and my throat felt like it swelled up every time I swallowed. Then everything turn this weird vibrant colour and it got really blurry. I got dizzy and could barely walk then for the rest of the day I had a horrible stomach,head and back ache. Why did this happen? It was about 12 and I had a bowl of cereal for breakfast at about 7:30.