My Mom’s Threatening To Call The Police If I Leave The House (i’m 18)

(i live in california) So since i was maybe 7/8 my mom has has cps cases against her for me and my older sister (20). Now im 18 so in my mind cps can’t do anything if i were to finally tell the truth. she verbally abused (still does) me and my sister (20) and always threatens to physically fight us but never has because we are MUCH stronger than her now. My boyfriend of two years and his family are ALWAYS trying to get me and my sister out of the house because they have heard me talk about what she’s done and have heard her scream at me on the phone. the thing is when i tell my mom or ask her if i can leave she says “if you even try to leave i will call the police on you and his family. if i leave and she calls the police can my boyfriends family get in trouble for taking me with them places? or will i get in any kind of trouble with the police? also if i ever tell her “mom im 18 you can’t lock me in the house im allowed to leave” she says “try leaving and see what happens to you”, is that a threat? its genuinely scary when she says it too, she towers over me and sometime acts like she going to hit me

(edit) i wanted to add something i forgot, i will sometimes tell her i can’t clean her room at the moment because im already busy cleaning the kitchen or something and she will SCREAM like violently scream at me. i always end up doing what she tells me to she just gets enraged when i cant do it that instant.