After what my sister did, I don't want her in my life anymore.
Can you explain what she did?
Don't tell me you forgot what she did. I swear she's the only person that even knows what I'm mad about now.
Well, I get that she hurt you and it's understandable that you would be mad but you're still family. You grew up together so you should be able to work things out. I'm sure in the end you would regret cutting off your sister.
She already ruined her life, I don't want her to ruin mine.
You need to talk to her and tell her why you are so upset. She might really need your support if she is in a bad situation. You might be her last lifeline.