Overhead phone call between GF and her cousin.

Me [32M] and her [30F], together 6 years, living together for 1 year.
I overhead a phone call between her and her cousin yesterday where she mentioned all the ?hot guys? she encountered when she used to be on tinder and then was making fun of the fact I was losing my hair and how stupid I looked in some clothing I wore the other day.
I was not trying to overhear their conversation. It was completely audible through the wall as I sat in the couch. We just moved into a new place.
I confronted her about it immediately afterwards. She tried to lie about it initially but then admitted it and said ?she?s just joking, that?s just girl talk and that?s just how she is?. She cheated on me 4 years ago with tinder although she didn?t end up dating anyone (I found all the chats).
I told her it was extremely disrespectful. Not only what she said but also the fact that she?s talking **** behind my back to her family.
Our relationship was seemingly going very well and we were talking about kids, marriage, etc.
When I confronted her, she just shut down and started doing random stuff on her computer. I told her I?m not wasting my time trying to talk to her if she thinks that?s an acceptable way to treat me. She kept staring at her computer and I left and went to bed.
It is now the next day and I am posting from work. I don?t know what I?m looking for here. I think it?s obvious I need to end the relationship.
Should I try to get another apology out of her and fix things or just pack my bags and leave?
TL;DR GF said some pretty bad stuff about me to her cousin and I overheard the entire conversation. GF lied then played it off now isn?t speaking to me.


Source.