I cannot stand my mother

Ok, so I'm a level headed person. I know right from wrong, but I'm starting to get violent towards my mother. I do not have patience anymore with her. I seriously think my mother has mental issues or maybe a learning challenge that she's in denial about.

I grew up in a violent neighborhood. She continued to stay there because she couldn't afford anywhere else, but I was constantly emotionally and physically abused. She never addressed the parents. My mom is the type to avoid confrontation at all costs and protect the other person. Fast forward to adulthood, when I speak to her, I have to always repeat myself multiple times. However, she's very attentive to others. She acts like a handicap baby that's incapable of learning and growing as a family. For example, she acts like she does not how to roll down her car window. It's just simple stuff. She is capable of learning but behaves in this slow and infantile state. I'm an only child so I feel like I'm stuck with this non-sense. She's always confused. She's always standing up for someone else. She never protects me, never! She's beyond passive. She's always making excuses for someone else. I'm tired of her weak and indifferent behavior. When I speak she looks off to the side many times and acts like I'm a nuisance to her. I am living with her temporarily and the hostility is just mounting.

I try to talk to her about what is bothering me like normal families and come to a resolution. She never works on herself. She's just mentally stuck. I'm so tired at this point. Help!