Hi,
73v3n. I’m sorry for the frustration that you’re feeling. It sounds familiar. Is she clinically diagnosed? One thing that might be helpful for you is to understand that her feelings are her own. Personality types like her will try to project her toxic feelings onto others because they don’t have the capacity to process them and deal with them on their own. Try not to take her actions personally. I know that it’s hard. After all, she’s your sister.
One thing that stands out is that you recognize that you can’t help her. This is true. I know that you would if you could, and you wouldn’t have mentioned it if you didn’t want to, but you know the reality of the situation.
https://bpdfamily.com/message_board/index.php?topic=111890.0Here’s a great link that might be helpful for you. It’s geared towards a romantic relationship with a pwBPD (person with Borderline Personality Disorder), but you may find some helpful advice in it. Read through it and come back here to share your thoughts and tell us what you think.
Welcome to bpdfamily. You’ve found a good place full of people that “get it”.