What Causes Headache And Dizziness After Recovering From Concussion?

hi ok so i got slammed from behind in a soccer game a couple of weeks ago and the trainer said i had whiplash so i was alike ok and she didnt clear me to play but i had a doctors apt and came home from school last thrusday because i was feeling very dizzy went to the doctor they said i have a concussion. my head wasnt hurting as bad for a couple of days. yesterday i went running and was feeling dizzy so i walked but i was also playing soccer yesterday and now today my headache and conceration and dizzyness is coming back. what is it? do i still have a mild concussion? should i attend school all day tomorrow?