#accountant problem

I think my classmates were angry to me b/c I didn't give them the copy of my financial accounting task and one of them said that friend shouldn't be like that and what I've done is not kinda good friend. I don't know, I just--I'm just tired okay, I just can't let my friends copy my work while I had done the task really hard, sacrifice my sleeping schedule and they just copy my work, like that? Should I be a bad friend and dont let my friends copy my work or should I be a good friend and let my friends copy my work--even I'm really angry inside myself?