She has to learn that she cannot keep doing this to you or anyone else. Otherwise she will go through life thinking it is ok to hurt people.

I suggest you only use words, communicate that you will not give in to her demands. Record the evidence on your phone if you can so that you can show your parents what is going on. They need to know that their daughter is doing this so they can do something about it.

I also suggest that you look up on Google good parenting skills, she needs to know that you are an adult and her behavior is unacceptable.

Failing all that, simply stay out of her way as much as possible but talk to your parents about the violence.

Oh and the counselor service at Uni is confidential so please look into that also.