Please help me

Hello,

My best friend, who we do everything together, has both bipolar and borderline, I have tried to help her through it for the last two years, hospital stay etc, we have had a few bumps in the road, but other than that, I look after her daughter when she is at school, we go for coffee, I was helping her sort her new home, and then out of the blue, she goes mad at me, and has blocked me on everything , we were having a lovely time at an easter egg hunt with my children and her children then she left us there and now doesnt want to be friends.
Reasoning is, in a rush a few weeks ago my dog was really poorly and I wasn't sure if she would be coming home, I sent a message to my friend saying not sure, if getting my dog back and going to see her, she sent s double question asking if I was going to see her before she was put down, I answered yes, as it turned out she made it through the night and was able to come home. Nothing more was said about my dog, she didnt ask about her and I didnt say too much as often the conversation is about her, a couple fo weeks later her daughter asked me if my dog was dead, I said no she had just been really poorly and we didnt know if she was going to make it through the night, a week later, my friend then at this easter thing accuses me of lying for sympathy that my dog had died! She said she had not mentiokned it to me since as she has no sympathy over a dog as its just a dog. She then said I was wierd and had wanted the synpathy vote, I said no it was a simple misunderstanding over messages, at the time I didnt know if she was coming back. She then went home and that night accused me of lying about my misccarriage last year which has devestated me. Basically she is saying I am lying on the anniversary date as I said it was the 24th, and last year I had said my miscarriage was the 20th, but it wasnt it was over a few days, 20-24th I miscarried so I have my choice decided to remember the 24th. She also accused me of saying it was earlier than this, I have proved it isnt, but then she just got defensive, I even offered to show her my medical notes, but she just said I dont give a $#%^ about your medical notes. She wants nothing more to do with me, Ive written her a letter, and given her tickets that we have booked together, I booked us a holdaiy so have given her the vouchers etc, but I am utterly devestated by this, she wont listen to me x