Damn. That sucks that you feel that way and today is your birthday. I had the same thing when I was in 4th grade. I actually ate pizza too, then threw it up and I felt like crap. My mom gave me cough medicine because she thought I was faking so I didn't have to go to school. She eventually brought me to the hospital and they said I was lucky we got there in time. Anyways I hope you feel better, I know how it is. Walking is a pain. Just get some rest and don't strain yourself.
Edit: It's not his birthday >:O
i'm sowwwy
:D