I need an extremely powerful emotional song.?

Im singing in an end of year assembly, and ive been going through a hard time recently which EVERYONE at SCHOOL knows about. I can sing really high(soprano but prefer to sing mezzo-soprano) and really low. Preferably a female song. REALLY POWERFUL hard song. with extremely emotional lyrics to show everyone how im feeling instead of them assuming im weak. If you undersatnd. Turning Tables by Adele and Jar of Hearts by Christina Perri were my first ideas but i would like something more emotional. to shock people. THANKSSSSSS <3 <3