OMG!!!!!!!! HELP I DNT WANNA DO IT 1 LAP?

Tommorow i was persuaded by my p.e teacher to do a wholee ONE lap around the school track its big for sports day! i really carnt do it i'm slow i have to do it infront of evvvvveryone the wholee school and stuff.. ireally dont want to do it i also get out of breath easily for like just running for 6 secs loose breath!!! this will take mefoorrrevver omg how do i tell my teacher i dont wanna do it???