Please help- family problems?

[Flugel]

Well, I get home and find my younger sis has left me a note telling me not to use her stuff! (written with my stuff i might add). usually i'd just go scream at her but i decide to go tell my mum who couldn't care less and took my sister's side. when i try to explain how i think this is unfair and wouldn't be dealt with if it was the other way round i get punished! then i go upstairs (shouting that it's all my sis's fault) my sis comes upstairs chasing me. then my mum shouts at me again. she then has a brief argument with my bro which results in both parents screaming at him n me. then my mum tells him that everything is my fault which i objected too because it is at least in part my sis's fault. i banged on the floor above them and my dad charges upstairs and slaps me a couple of times. now i'm upstairs crying with no-one to talk to. any advice here is welcome