Anyone know anything a bout blackberry's ! please help D:! seriously or im dead?

well , im 14 and i was in gym getting ready to change just as i was about to change i tripped over my pants ( dumb move) and feel on my fone D: the screen is black with red and green lines and my friend tried fixing it and now its just white blank the problem is if i tell my mother she will killl me ! we're completely broke! we have no money and im really scared please help!