Abuse??

So growing up my whole life my parents fought like every other couple. But when it comes to my mother she is crazy I say!!! She's laid hands on me multiple times... I even moved out for a while over it... anyways lately she's been saying crazy things about me being a hoe calling me so many names like she always has since I was younger. She told me not to be a hoe and that I better not get with my boss who is married. Which hurt me to hear my mother accuse me of such things. Well at the moment she's sort of left me alone because I'm always working now but she started going crazy with my dad. My dad is a religious man and treats any of my close friends as his own and welcomes them into our home. . One of my friends always comes over. We al go to the same church and EVERYONE hugs one another at church so when she comes over she hugs my dad and says hey to everyone else but my mother started accusing my father with my friend which is so embarrassing. I had to stop bringing her over because of it. One day my mother almost told my friends mother that my father was "seeing and fucking" their daughter aka my friend which is NOT true at all. It was really disgusting. Point is she's always accusing us and hitting on all of us including my father. He's extremely sick and God only knows how many more years he's giving me with my father . She's always hitting either me or my father. Calling all of us names. She use to talk to a man still sorta does and I think she brings rage towards us because of her guilt. She manipulates my little brother and he literally went into depression. I've had to take KNIFES away from him at some point because of how crazy she's made him. I believe she's an abuser. But I don't know how to fix the situation or what to do to help her ??? She's threatened to kill my dad a couple times and so on. I think my mother is mentally ill. What do I do:(???