I hate my little sister
She's your little sister, why would you hate her?
She is stupid and arrogant, also she is trying to be better than me
Brothers and sisters fight all the time. It's okay to be upset from time to time, but know that you need to get over this and maybe find things you can relate with in the future.
I know but I can't stand it any more. If hell froze over right now and I saw her, I would still hate her.
I don't know what's fully going on between you two, but I still believe you need to reconcile in the future. Even though you may not get along which is okay, she is still your family and you'd always be with her no matter what. Don't you want to make happier memories instead of angry ones?