not the end of the world really but if perhaps you can repeat the year altogether or take summer school, it'll give you a chance to pass the year. Its crap to repeat a year, I know but look at it in the sense, better make up for it now while you still can instead of finding yourself having a hard time getting into college/university and then ultimately making it difficult to get a good job later.
I regret not listening and paying attention at school. It's not helped me one bit now.
Definately good advice really, just keep your nut down, get on with it and you'll do alright. School might seem to go on for an age but it's pretty much mandatory, once it's done with you're pretty much free. I know not everyone can pay attention and do the work aswell as others but everyone can try their best.