I've 30M broken up with my girlfriend 25F but she still refuses to accept.

How can I make her understand its over between us?
Context:
Three weeks ago my girlfriend and I had a weeklong argument that had been weighing me down and I finally told her I wanted to break up. She thought I wasn't being serious but I was. My main reason for this is I think she'll never respect me. On our last day she kept trying to diminish me and showed me a lot of disrespect which honestly I can't tolerate. She moved in with me two months ago after two years of knowing each other and maybe things have gone really badly.

Recently she has exhibited signs of emotional instability and sent me really concerning messages about how she wants to harm herself. The whole thing has boiled over i've had to involve her family which she's ignoring trying to mend things with me.
Currently she's camped outside my home and I dont think I'll let her in. (Give her an inch she'll take yard). She had gone to live with an acquaintance but I don't think that had any hope of transpiring. For financial context we're both freelances but last few months she's been doing fairly well, much better than me and if she wanted to rent a place of her own she would but she always wants to be living with someone.

I think to even consider having her as a girlfriend again, I think she'll need a therapist but currently just having to constantly have my phone off is really inconvenient. Does anyone know what I would do as the next step?