my world is forever shattered

I cant sleep. Every time I close my eyes bad things happen.
 Earlier tonight the worst thing  happened. My entire world shattered. My sister who I loved dearly hasnt spoken to me or come near me since I started to discover I was/ am biplar.I've been hospitalized 4 times now. She hasnt been there for me for any of them. Then out of the blue today she texted me. Yes. I was so happy. Maybe, finally we could start mending our relationship. but no. she doesnt want that. Instead she says she wants me to stay away from her children. Can u believe that!? I love my niece and nephew so much. I have no children of my own so I've always thought and loved them as though they were my own. since I started having my problems I havent asked sarah if either of them could come over. I havent even been alone with either of her kids for over a year. Now she tells me that I can never see her kids again unless I'm supervised by another adult. I cant believe this is happening.
I feel as though my life is over. I just want to curl up and die. How could she ever for even a second think I would hurt them or anybody for that matter.
When I got the text I felt like I couldnt breath. I started crying so hard I thought  I might pass out. When I stopped crying enough so I could talk I called her. I was very upset. I yelled a lot at first. She kept cutting me off and interrupting. I really hate it when people interrupt me. makes me so angry. I had to yell really loud before she shut up and let me talk. I tried to explain that I wasnt myself. I tried to explain the bipolar illness. I offered to  send her a book. No. She doesnt like to read. Instead she told me that I'm crazy and untrustworthy.
She said she'd been thinking about this for a while and has come to this conclusion. I know my sister. Once she makes her mind up about something she wont change her mind no matter what anybody says. And if I try to change her mind again she'll just hate me.
I told her fine. What could I do? She's their mother. My heart is now broken in two. Its as bad as if she told me they were dead. In a way they are. I can only see them in passing now. I know my mom. She has always been a people pleaser. She wont do anthing to displease Sarah. So my fate is sealed. My neice and nephew are practically out of my life.
So I told her that from this day forth she is no longer my sister. I will not contact her again. I erased her phone number from my phone.
After I hung up with her I called my mom. I told her what happened. She was shocked. She said a few encouraging words. Then I called my friend SH. She's the most encouraging. She even prayed with me. I told her I didnt want to be left alone tomorro. I dont tust myself. She said she'd pick me up as soon as I wake up. After that I called my mother-in-law. I told her what hppened too. She also made a few encouraging comment. I dont know why I felt the need to call all my friends right now. I think I just needed somebody to tell me that I'm not crazy.