What could be wrong with me?

Just lately i have been getting REALLY bad stomach cramps. I have been coughing up phlegm, to the point its actually choked me a few times. Im sweating extensively, and im getting tired really easily. The other day i was in an athletics contest. Which im usually really good at. And on the 800 meters my throat just closed up, and i couldnt breathe... And i ended up in the first aid unit. Also im constipated, which is discusting :S And my ribs are aching like crazy! No theres no chance i can be pregnant. And there is no history of stomach problems in the family, apart from my mum suffering from hernias.