being mature for your age - feeling trapped as a young adult

i’m not sure where to post this so i’ll be posting it in couple of groups.

i grew up in a broken home and had to grow up fast for the sake of my younger sister, who i ended up raising during my childhood since the day she was born. i’m 19 now. i’m still practically her parent. i grew up with my parents fighting all the time and they are still together and not much has changed. i put a hold on moving out once i got into college for my sisters sake. i was always told i was really mature for my age, ever since i can remember i was always told that. my parents keep a tough hold on me even now especially since i still live with them. my dad says that the second i fuck up im going to get kicked out of the house meaning if i fail in my classes, if i get pregnant, or essentially if i make an adult decision without their approval. being mature for your age ends up being a burden, well at least for me. i see how more mature and a lot of times i’m compared to someone whose 10+ years older than me. i’m 19 with a mind of a 40 year, is what i’m told. i’ve always wanted kids and i want to get married and have that life. my boyfriend and i have been together for 2.5 years. i’ve made a post before about a year back talking about this and wanting kids but i only got hate since i’m so young. i know i’m young but it’s hard when you think like someone older than you and want that life when society and your parents standards say what you want is wrong for your age. i hate feeling so trapped in my mind when i shouldn’t have the things i want despite “being older minded” i guess you can say. if someone relates to this, do you have any advice? i could easily move out and leave but i haven’t for my sisters sake and i know i shouldn’t do that but it’s hard to leave just like that when im still practically raising her and she’s 15 now. i feel stuck and trapped and not sure what to do with all those feelings other than bury them as deep as i can. i guess any advice will help as long as it’s helpful

please no hate or “you’re too young to think like that” sort of comments because trust me, i know, that’s the reason i’m writing this - i got enough of that the last time i talked about this