Feeling guilty

Looking for some advice. I had a friend who unknown to me throughout our friendship had long term mental health issues. She met a guy on an online dating service and they met once and had sex. He made it clear to her that he was not looking for a relationship beforehand. Afterwards he did not contact her and was not reading her messages she was becoming increasingly agitated, I tried to reassure her that maybe his phone was broken or he had a family issue, so she asked me to message him via snapchat to see if he replied to me, I did not know this man but I did as she asked and he replied immediately to me as she instructed I pretended he had given me him username in a bar one night. He was telling me I was a beautiful woman and asked me out. I said no and deleted him at this point but she had asked me to screenshot the conversation which I did, this sent her into a rage and she sent him abusive messages. A week later she was still crying and saying that she wanted him back etc that she hated the thought of him hating her I thought this was strange especially as it was a one night stand but she wouldn't see sense and when he out of the blue messaged me on another social network site I apologised for my messaging him previously and asked if he would see her again but he said no I asked if he would message her just to tell her that he didn't hate her which he did but he also made it clear in his message that he would not see her again. She seemed to feel better after this and several weeks past and she went on a few other dates, I continued to talk to the man every few days or so we got on well and 3 weeks later met for coffee. I didn't tell my friend about this at the time, then suddenly she started accusing me of sleeping with him posting disturbing material on twitter about stabbing a friend who betrayed her etc so I confronted her and she said that he told her I slept with him which I didn't and he denied saying this to her I admitted to meeting him for coffee which sent her over the edge and she blocked me from everything however I had an old twitter account which she was unaware of so I was able to watch her account the things she said about me were horrible and cruel I spoke to a friend who was a police officer as I was becoming concerned for my safety due to what she was saying and he said because she wasn't actually naming me nothing could be done but to screenshot everything just in case. I have done for the last two weeks the posts have become more and more worrying saying she was self harming and suicide and I finally spoke to a professional person a few days ago as I was concerned for her young children that they were going to find her dead. However that same day she tried to commit suicide by jumping off a bridge into a river she was rescued alive but I now feel enormously guilty that I didn't say something sooner and that I've cause all this by having coffee with the guy. In her head he was her boyfriend and I stole him from her which I didn't and I have not seen him since we went for coffee. I did not know about her ongoing mental health issues if I had I would have spoken up sooner, when I think of what might have happened I feel like the weight of guilt is all on me. Was this my fault?

If I tell u it wasn't your fault then I will be lying. Yeah shit happens. She knows u had coffee with this guy before u could tell her yourself. "That's a date" U have been chatting with this guy more than she asked you to. "That's betrayal" Atleast she expected you to show her more of your discussions him, if u have no foreign thoughts. If she tells this story herself, we all are gonna call u bad names. I also want to c things from her point of view. Like I said earlier shit happens and the did have been done. ****please take note I'm not trying to put the blame on u. I know u were trying to make her happy by talking to this guy. Good intentions. But your approach was not appropriate. But it has happened. Take it as lessons. As for her reaction, Well we might say it's due to her mental health issues. But u still gat alot to do. When she tries killing herself and fail, next will be on the person that "coused" it. Tell your police friend to help you get in contact with this same innocent boy. You both and the police or any legal authority should go meet her. Then let him explain to her that you have nothing to do with him. Just to clear your face. It's gonna feel better to her atleast it's not her friend that's stealing her man. Then it's not your business what else they talk about. Get back for any opinion. GOOD LUCK