I don't trust my sister and I don't want to talk to her.
For what reasons do you not trust her?
My sister has betrayed me lots of times.
Your sister is wrong to betray your trust. It's normal to keep in contact with family but you don't have to be around people who betray you.
Also she talks of me behind my back. She doesn't give a shit about my feelings.
It's unfortunate your sister has treated you this way and your feelings are valid. It's good that you have set boundaries in order to prevent yourself from being hurt in the future.