I dont know what to do

my best friend is not talking to me and I dont know what else to do. we've known each other for six years and have been through a lot together. i dont have any family and she is a large part of my life. I am bipolar and can be difficult to deal with although she isnt so easy either. weve had fights on and off for some time now. about a week ago we got into a fight and i told her i didnt want to put up with this anymore but only because i was mad and in response she said something very hurtful. ive done some things out of spite but nothing too detrimental. i apologized to her in a note but she still refuses to talk to me. she wont even tell me why shes mad and i dont know what to do. i am currently very sick and im fearful that i dont have long left. its so hard to go through this all alone. i have other friends but they arent there like she is. i dont want to die with her hating me. what should i do to fix this? should i just give up?