What to do about my evil family?

my mom and sister constantly berate me.they write evil things all over facebook about me.my mom calls me a piece of **** and says that she is going to have all of my utilities shut off,they are in her name cause i am sick with lupus and i could not afford to have them put in my name after she moved out,cause my meds are too expensive.i am worried.what will i do? they call me mentally ill and say that i am making the illness up.they post this all on facebook.i am so ashamed and embarred. i am worried about what i will do when my mom shuts off the utilities,which I pay for,even though they are in her name.i will ahve no phone to call an ambulance if i get ill,no heat for me and my kids.as i said, i pay for these.i have never asked her to support me.i just can not afford the deposit to HAVE THEM PUT IN MY NAME.they now have my whole extended family calling me names such as piece of ****,coward and munchasan syndrome girl. i am so hurt.what should i do? isnt there a law against slander on the internet? my friends and colleagues,and my kids teachers can all see this,it is humiliating.i am very ill right now with hemolytic anemia from the lupus and i cant handle this.