<human>: Can you condense the text into a few key points?

Earlier in september, I met a cute girl whom I really got along well with and liked. However, i had a girlfriend at the time and was busy with school, work etc. and did not take her invites to hang out. 

Fast forward to december, I finally had the time to meet her. But now I realize that over the few past months, she has been cutting herself, getting drunk every weekend, having sex with lots of random guys, etc. for attention, I assume. 

We met up and she got drunk and simply offered sex within 1 hour of meeting up, which I did not take... Now I feel both regretful and guilty, as I could have been there earlier to stop her from doing these and also to actually be with her. She just sent me a message asking me to not talk to her again because the offer was a one time thing. What should I do now?
<bot>: Met a girl, didn't act on it, she turned to self harm and sex/drugs/alcohol. Now im regretful that i missed the chance to date a wonderful person and to help her life...