*Probably the wrong section, if so, sorry*

I'm 15, don't smoke, drink or anything like that; and my BMI is 19.0 so I;m FAR from overweight; have Asthma.
When ever I exorcise, especially run, within around 1-5 minutes of running I get a bad sore, choking type feeling in my throat (Its a feeling as if I'm about to be sick, or already have been; lasts around 3 hours + from stopping, depending how much energy I put into running), with that is a really bad headache that intensifies and causes my vision to go slightly blurry for awhile; (Headache, around 2 hours, Vision for 1-2 minutes, but its still a little fuzzy now, and it was 4 hours ago last time) Also a sharp stabbing pain in my left side. (Like really bad stitch, lasts around 10 minutes)

I get constant headaches sometimes, but that is usually because I try to overwork my brain.

Any Ideas what it is? (I saw a doctor, and he said it was probably due to the stress of my exams, completely forgetting how I said it's been happening over a year, longer than exams have been on my mind.)