 My mom has paranoia, maybe Paranoid personality disorder, and apparently her mom had it too (undiagnosed). Anyway, her behavior has become even more erratic than it was when I was younger(I’m now in my early 20s), and I think hormonal changes due to menopause may have exacerbated it. She is not only paranoid, but also selfish, narcissistic, immature, and lazy. Anyway, her paranoia is taking a toll on my family (dad, brother, and I). Her paranoia has always been directed at my dad’s side of the family. She says really disgusting, vile things about them; I didn’t even understand the statements when I heard them when I was 11 because they were so foul. My paternal grandparents only live 1 hour away, and I have a great relationship with them, but they know I can’t let them come over because my mom despises them (I’m currently living at home and working remotely). Her paranoia has convinced her that they’ve been stealing money from her, talk about her, and hate her, and she even wishes death upon them, which is very hard for me to hear and continue to love her. She can’t make any friends either, so my dad doesn’t have any friends. If they do make friends, my mom will eventually tell them off after a few months because she “knows they’re talking” about her. She has even told me she hopes my dad and his family die. She makes me dad out to be the villain and he hasn’t done any of things she says; we’ve even shown her proof before, and she thinks of some other narrative to justify what she “knows”. I’ve even seen her throw things at my dad and hit and bite him. When I tell her she needs help, she says, “You need help.” She’s very much against seeking help because she thinks everyone else is crazy, not her. Whenever I tell her what she has done or said is wrong, she says emotionally manipulative things, and it’s very taxing—leaving me feeling guilty and confused. 

How can I get her help? She is ruining my, my dad’s, my brother’s, and my paternal family’s lives, and I don’t know how much of a relationship I can sustain with her later on. We live in a state of anxiety because we don't want to do or say anything that will set her off. I can't even take calls from my grandpa in her presence. She’s nice and loving when she’s not being crazy, but if she continues down this path, everyone she loves will leave her. 

Thanks for your help because I’m out of options and exhausted. 

Tldr: My mom is mentally ill (PPD or paranoia) and desperately needs help. How can I get her to seek help for her and my family’s sake?