Defamation? Libel? Harassment?

There are two people posting false statements about me on the internet (I have screenshots and proof). These statements are false and include links to my online profiles. The statements also are said in a way to incite anger and hostility towards me from others and then include online links and personal information where people can contact me and find me in person. I have sent cease and desist notices to both parties. One acknowledges the cease and desist by discussing online and through text messages. The other party refused the certified mail with the cease and desist inside. This is harassing, embarrassing, and harmful to my profession. I am a teacher and one of the parties posts false statements on social media to my professional peers regarding my treatment and personal relationship with my step daughter. There is much more they are saying and doing. What can I do about it? What's my next step? BTW..These are my in laws and we have a current trespassing against one of the parties.