abusive relationship

My current girlfriend of 4 years has done a lot of hurtful Shit to me in the past from cheating lying and hurting me physically and emotionally.
She has a bit  of a narcasstic personality!
We have to msg 24/7 when at work cause otherwise she thinks I cheat on her. If I take legit 3 minutes to reply it's " what have you been doing or doing "
She always assumes I'm talking to other people ( I have never done wrong by her ) but instead take her back million times.
She told me the other night that she owns me and I'm her property. 
Sometimes I get the urge to cheat on her so I can finally find the strength to leave !!! But I'm not a cheater :( 
I'm nearly 25 and all I want are kids :( 
* this is a lesbian relationship *