I hate it here

So basically I live with my boyfriend and his family, his sister comes to visit every now and then she lives with her friend in a small apartment.

My boyfriend and I live in the basement as he’s in school and I’m saving for our apartment.

His sister will come over and they usually play video games together but honestly everytime she comes over she’s just completely rude to me and I hate being around her. One time they came down to the bedroom and played video games at 2am and they woke me up and I said “can you guys please keep it down I’m trying to sleep and I have work in the morning” his sister then proceeds to scream at me after her brother turns off the game and says “we can play after”

She continues to yell at me then starts yelling “ CHOOSE ME OR HER” I couldn’t believe it I literally had to pick my jaw up off the floor because the insanity was too much: but this weekend I’ve been constantly spoken to ignorantly, my boyfriend makes promises with me but then continues to push it to the next day cause she promises to play games with him but then never does so I’m stuck doing nothing on the days she’s here and when I get upset about him promising to do stuff with me and he cancels to pay games with her she gets upset and starts yelling at me.

I cant understand it. I’m constantly miserable cause I feel absolutely hated I feel she only tries to be nice to me cause I’m her brothers boyfriend. She treats me like absolute shit but when holidays come she’s nice I physically cannot deal with it. I’m tired of being yelled at, I’m tired of being judged, I’m tired of my plans consistently getting canceled so she can bail on the plans she made that night and continues to push them to the next day.