Bf’s narcissistic psycho fam.

I’ve been with my bf for 2 years now and for a year I’ve had to battle with his family non stop. We’re young, 18 and 19 so we haven’t moved out and kind of have to accept each other’s families. Before it used to be just his mom talking shit behind my back but the last two days I have reached my limit. My boyfriend, I, his little sister (13) and his little brother (9) were hanging out in his room while he played some video games. His other sister (16) comes down and starts yelling at the 13 year old for no reason making fun of her and just being stuck up, so the 13 year old looks at me and says I wish she would shut up, so I replied with I can’t say anything you know that. His 9 year old brother starts and tells the 16 year old “oh ____ told you to shut up” as in me. Which I never did. So then the 16 year old goes, “stfu bitch and gtfo of my moms house then”. Her mom doesn’t even tell her to stop or tell her to stop disrespecting me like that she just agrees saying I shouldn’t be talking to her like that and yelling at me. The next day, I took his little sister (13) to my house and the mall. She needed a break because her mom and sister are very verbally abusive always calling her names and fat pig, etc. Mind you this girl is healthy weight, around 105-110lbs. Her mom got mad at me because she wanted the 13 year old to stay at home and watch her sisters (24) baby while they go to the mall and leave her all alone. Fast forward, I bring her home around 6:30pm and she had the best day with me, I bought her stuff to make her feel special. She knocks on the door and his mom unbolted the door but doesn’t open it and she runs upstairs, not even waiting for us to get in. Usually, I would say hi. So I waited in the kitchen for her for 5 mins and when she didn’t come down I went to my bf’s room which is in the basement. Once she hears I’m in the basement she comes downstairs and screams at the top of the stairs, “you’re a ignorant fuck, comes into my house and can’t even say hi. Who the fuck do you think you are, you walk into this house like it’s your own your so ignorant, like fuck you”. Then she starts attacking 13y/o, “go live with your dumb fuck friend (me) you two ignorant bitches”. Like how can someone speak to someone that way, I’m not even her child. She acts like this because I wouldn’t drive her to pick up something because I had class that day. Nonetheless, I would’ve said no either way because of the way she treats me and she never pays gas. My bf got mad at me saying I should’ve just screamed up hi, but with everything that happened the day before I was not comfortable and especially with his mom running away. I told him I’m not going to chase a grown ass woman, and I’m not going to respect his family if they can’t respect me. He still hasnt said anything to his mom about her behaviour. It’s gotten to the point where it’s affecting my mental health being bitched at for no reason. And I feel like I’m done.