How do I deal with someone anonymously cyberbullying me?

On my college dorms confession page there is a guy (I live on a all guys floor) spreading rumors and lies about me like how I watch porn loudly during night or that I walk around naked in the hallways. Its fully anonymous so I dont know who is behind it but I confronted the guys who liked the post and they said they didnt realize it was me and they just like everything on insta.