Erasmus - Sticky Situation

Hey guys,

So I study Commerce and Spanish in UCC. Im on erasmus at the moment in Spain. The first semester was fine, good fun, and had little to do with the college here. The college here are terrible - do everything in their power to make us drop out of their classes (They hate erasmus students). So anyway, basically I have been considering just going home, and coming back in may to do my exams, which I already know I am going to fail.
I have heard that if we fail our exams on erasmus, all we have to do is write an essay based on our experience as an erasmus student?
They can hardly send us abroad again for another year?

I really dont like my course as well so I was looking at just finishing up and starting a new course, but I know my parents couldnt afford for me to start from fresh again. Does anyone have any ideas?
Thanks