I am so overdone (sorry long read)

My “best friend” has been living with us for over a year now and I have been so depressed since the day she got here and shes a know it all, rude, ignorant, racist, has a huge ego, immature, oblivious, and highly annoying and the biggest bitch. And now she keeps posting things on social media directed towards me and I’m so overdone and exhausted emotionally and mentally. I’ve been literally avoiding her like the plague for over a year because I can’t stand her and she gives me no space so I have to isolate myself and starve myself to just avoid her and be alone. When I talk to her it goes through one ear and out the other and she talks to the friends we share about how I’m ignoring her for no reason at all and how she’s such a victim so then I get personally attacked by these so called friends. She also has a councillor and people to talk to and she gets to see her family often meanwhile I’ve got no one because everyone takes her side including my parents and I don’t even talk to anyone about this because it’s none of their business and plus people just automatically take her side out of pity without even asking for my side of the story. I have been bottling all of this up for over a year and I’ve become so depressed and suicidal and I’ve got no one to help me. I have talked to my parents many times but I’m always cast to the side because they don’t have time for me because apparently I’m easy to forget about and I listen so they don’t notice me or give me attention at all. And every time I try to talk to my parents my “friend” cuts me off mid sentence to talk about herself (did I forget to mention she’s also an attention whore and self absorbed🙄). She’s so immature and will do anything for attention and acts super trashy and like a slut for attention and it’s sooooo annoying!!! Like I said when I talk to her it goes in one ear and out the other so it’s pointless and then she talks more shit about me. I used to be a loving, calm, caring person but she has made me into someone that’s hateful, angry, and I distance myself from everyone completely and I don’t want to be that type of person because I like to forgive people but she has caused me so much pain and sadness that I can’t just move on from it. She recently became really mad at me cause my mom and I were fighting and I could hear her stop what she was doing to come eavesdrop and I could hear her at the bottom of the stairs so I yelled for her to stop listening. And then after that she was having a little temper tantrum cause she’s immature (btw she’s also 17). And my other friends ( except for one of them which talked shit about me for an hour because he only listened to her and then tried to play the victim when I lost it on him after listening to all the things he was saying about me) just recently saw what I’ve been going through and they apologized for taking her side in the beginning. And they are angry at her too because we threw a party and she sexually assaulted and harassed almost all of them. Now I just found out she blocked me on all social media after my friend told her to stop posting things about me and I can’t ever be comfortable in my own home cause she lives here and she makes my life miserable and my parents don’t ever listen to me or care about how I’m feeling and when they do care nothing even gets done. I’ve been trying to move out for a while but they won’t let me and I have nowhere to go. With this quarantine shit going on I’m now stuck with her for 24 hours a day and I’ve already started to go crazy. I’m so depressed and suicidal right now and I’m scared if I stay here any longer or if she lives here any longer I will kill myself. And when I talk to my parents about my mental health and my suicidal thoughts all they do is threaten to take me to a mental hospital which doesn’t help, all it does is make me more depressed and makes me bottle up my feelings more. Please suggest ways to help me. I cant keep living like this. And this post just shows a little of what’s happening cause there is so much more because it’s literally a living hell. Im so broken and I cant keep living like this and I need help.