Schoolmates are destroying my reputation by spreading gossips

Atty, what legal step should I do after knowing that these people, particularly my schoolmates and classmates are spreading rumors about me that I'm unchaste, gold digger, prostitute, have been pregnant, which aren't really true. It's really bothering me since I see these people regularly, and it traumatized me because I am not used of having such issues, and as my family said, nobody has the right to judge me and destroy my dignity. However I knew it through an acquaintance who hacked the facebook account of A who was one of those who dishonor me. A always had conversations with B through facebook private messages. So with the skills of my acquaintance, he/she told me that I'm always their topic; talking deceitful, stupid and negative comments about me. But of course, that acquaintance I'm pertaining to doesn't want to be recognized. I'm a girl and it's threatening me since my classmates and other people are now avoiding and mistreating me just because of these rumors. One time, I was at the school garden then someone from another course, poured water on my side from the second floor. But when I was about to check who did that, that person was gone already. I was clueless who was that, but one thing's for sure, I know what course that person is taking. Please help me.. I would appreciate your advice. Thank you and God bless!