What Is The Treatment For Cough And Lightheadedness?

i am 35, never ever had a fit, just a few hours ago i started coughing and felt lightheaded, next thing i know is i feel weird with a bad headache, my partner said i flopped into chair and me eyes went up into back of socket, then i suddenly stiffened up and started shaking all this happend in around 20 seconds, all i was doing when this happened was having a cig and watchin tv, just wondering if anything serious or this can happen if never fitted before