I have fallen out with my best friend / sister, how do build back bridges? Please help!?

I have been very close to this person for a fair a mount of years now. she has always been there for me through good and bad times helping me with my insecurities building me up from a very depressing time of my life she has been my foundation to lean on to keep me going I have so much confidants since being friends with her and feel i can do anything when we are friends because she stands by me. I am always here for her no matter what, very loyal, and somone to have fun times with when im on top im the most loving bubbly person u could meet but when I'm low im rock bottom. she values the friendship too but wants out. we have had silly fall outs and managed to over come them and be just as close, like normal. But this time she has said that she doesn't want to be friends again, she wont meet up with me and talk. even though not every time we fallout is my fault she makes me feel like its all my fault leaving me feeling alone hurt and useless and hating myself because of it. I really value the friendship and want It back so I can be happy. Please give me some advice that could help. Thank you for your time. xI have fallen out with my best friend / sister, how do build back bridges? Please help!?
This has happened between me and some old friends. But neither of us said we didn't want to be friends anymore. We were just completely close friends one day, and now we barely talk. I'm really sorry about the situation you're in. My best friend posted a question like this a few months ago. We got in a big fight and I started hanging out with other people and she did too. She still wanted to be my best friend but I had another one, a better one. She was really sad because she thought I was still her best friend but I didn't think about her too often. Although now everything is back to normal. If you really want to be back with your best friend, ask her if she's happy with her idea. If she's sure that she's ending this friendship after years of friendship. If she says that she is happy, I guess you can't do anything anymore because you should be happy if she's happy. Try talking to her ASAP!