Do i have heat exhaustion?

today it was almost 100 degrees and i was outside for 8 hours in the shade.but it was still really hot. i had to run a race for track and when i finished i was hysterically cougihng for an hour straight, dry heaving and gagging and spitting everywhere. now 6 hours later i feel horrible and am still coughing a little. i have a headache and am sweating. what is wrong with me? i was completley hydrated last night and made sure i drank alot today during. please help im scared thank u