My best friend hates me so much

I am a PhD student. This summer I had to stay at university; my friends went home and I was far away from my family. I was so isolated and hopeless. Then my friends came back; my best friend (she) came back. I was so happy. She wasnt. She was struggling and didnt want to be at university anymore. For 2 weeks I listened. Finally I thought I would help, and offered some advice. I said before making such a big decision, try to think of the good and the bad. Try to make sure its something you really want, and not something youre feeling specifically at this moment in time. She responded with abuse and threats (‘I dont need your approval to do something. ‘You cant tell me how to live). This sent me over the edge, and my hopelessness spiralled and I had an emotional collapse. I cried all the time and was close to suicide. But I came back. I tried to contact her to apologize. I know Im not perfect and I concede I made mistakes. But no reply from her. She was a ghost. She is someone who is on social media all the time. I noticed she wasnt anymore. I was afraid something bad happened. I sent her gifs everyday saying ‘youre a good person, ‘youre a special person hugging gifs; hoping to make her know someone cares. She unfriended me, and threatened me. She hates me so much. Ive made mistakes, and I would do things differently if I could go back. But I cant. I cry all the time, I cant sleep or eat. She doesnt talk to me; looks at me like Im dead. Help