I am seeking help for my sisters depression... She has been in a relationship for a few years and her man no longer wants to be with her yet they keep seeing each other. I have asked him to please stop seeing my sister so it helps her move along and I have asked her to please stop seeing him but you know the heart wants what it wants. It's sad how one person can just break you into pieces to this point. She's gotten to a breaking point where she talks about harming herself.... A good friend of hers text me and asked me to help my sister and my sisters "boyfriend" also text me to help my sister. I have tried talking to her. I asked her to sleep over and she tells me to leave her alone, I ask if she's hungry I'll cook for her she says to leave her alone. I asked her to please help herself move along and she responds with a "fuck you. Leave me alone". She doesn't want to talk to me she only gets angry. I have said so much I even talked to her in the car for 2 hours, she cried and hugged me...I thought I helped then and there but now it's just getting worse

How can I get her to listen to me? She is very short tempered and stubborn, loves attention, it's either her way or the highway.. her responses frustrate me so much but I want to keep helping her. I also just messaged her and said I want to talk to her and if she's more comfortable texting it's okay too and she responds "sure. Now leave me alone".

This is not the right place to ask..I know..but if a comment can help...

I am doing more to help too just don't want to get into too much details.