I hate my sister

I'm always nice to her and she is always mean and rude to me. I don't know why she is like this to me, but she is a bitch towards me. She spit out insults to me and I've learned to suck it up. But when I say a comeback she starts getting angry or get's really offended. I can't go one day without hearing insults and her being mean towards me. Whenever I go places she expects me to get something for her, but she never ever returns the favour whenever she goes places.

We're both adults (I'm the oldest) and she says I need to act more like one. The irony is that she acts like a spoiled child whenever nothing goes her way and in general. But also I've done more adult shit before she even moved out of our parents house. To even add more she constatly needs my help, like she is a child that always needs their hand to be held.

I hate being the oldest and I'm tired of constantly sucking up shit from her. I hate it how I try to talk about the problems she either closes her ears or says that I'm overreacting. It feels like she thinks that the world revolves around her. I can't have a peace of mind when she is around. It feels like no matter how hard I try to avoid interactions with her, she just disturbs me and acts like a bitch. I am genuinely being nice and all I get is a bitchy attitude. She never does something or says something nice to me. I can't even remember the last time she genuinely were nice to me.

Just a small vent I have wanted to get out for a very long time. I'm getting genuinely frustraded and sad because of her.