Help I Have The Worst Sister Ever

I'm 15 soon to be 16. She is 19 soon to be 20. She is a heroin addict and has never been nice to me ever. She used to hit me and shout at me and scream that i'm adopted so much to the extent i still often think that i might be adopted. She is one of the people who love to hate authority etc. She has all these philosophical facts and theories that she tries to force on me. She basically tries to make me more like her and she thinks i'm depressed and a horrible person. She blames it all on my mum and dad. She lives by herself in a flat (which my dad pays everything for because she won't get a job because she refused to be a "corporate slave"). She always comes to mine and my mums house (parents divorced), to dye her hair (we don't want her to!). This happens literally every month and everytime she does nothing but make me and my mum miserable. She can't say anything nice to us and strives to prove us wrong. Today i came home after a nice day at school to find her make up etc. spread all across the tables and the bathroom and her dog there. So what did I do? I looked in the living room and saw it all and just left. I walked to the supermarket where my mum goes to get food after work and waited half an hour for her outside in the snow because i couldn't bare to be with my sister alone. I was so confused and upset. It's sad how much she can effect my mood. I rang my dad and mum and dad knew she was coming but thought she would of left by now. WHY THE **** DID HE NOT TELL ME OR MY MUM SHE WAS GOING TO COME HERE I MEAN WHO DOES THAT. She NEVER leaves when she comes here NEVER. She says she is here to dye her hair but she has been here all day now (it's 8pm now) and she still hasn't. My dad argues that she doesn't like being here and only wants to die her hair then leave. This clearly is not the case if she brings basically all her belongings and her dog, but he defends her so much that it's like he encourages her to stay here. I need to go in the shower but her stuff is all over the bathroom and i don't even want to talk to her so i don't know what i can do. And please don't feel sympathy for her because she is a heroin addict, she was like this for her whole life if anything heroin and made people feel sorry for her for being the way she is. I just want her to leave. She has a back door key by accident so that's how she got in. Mum is getting the locks changed this weekend and hopefully i will never have to go through this again. My dad doesn't come back from his work trip until friday and because she lives half hour away he gives her a lift so her going home before then is looking doubtful. I hope to god that she leaves tomorrow. She thinks im depressed but really i just seem like that because whenever she is here i'd rather be getting my leg amputated.
You may not think she sounds so bad but there is too much detail to describe and this is just making me unhappy. Basically, I want nothing to do with her when i'm older. I will do everything in my power to assure i never have any contact with her.
An Ep User An EP User
Jan 16, 2013