If I didn't work hard enough, I guess I wouldn't even cry and just resit and try my best.
If I did work hard and still failed, I would look into progressing through apprenticeship etc.. to climb the career ladder in some firm but it's really unlikely that I will do bad if I worked hard, because I believe everyone gets what he puts (in general).
The worst think would be facing my parents dissapointment, after all the years of studying.