freidn upset please for the love of humanity help

ok my friend whom I care about more than anything in the whole world was just dumped. He now ex-boyfriend told her that he already had a girl picked out. He has been hurting her for god a week hanging out with this girl that he admitted to liking and told her he would go out with this girl if tia and him did not work out and then comes up with thsi bs about "not feeling the spark anymore" i know its bs. I dunno what to do she is begging me to tell her how to cut and i hate kyles (her ex and one of my friends who i thought i could trust to keep her happy) guts so effin much now i feel guilty for introducing them and encouraging them to go out. I am so ugh just help

I know, but it is my fault i knew that kyle did the same to Dara but he seemed so repentant about it he swore, ive treid talking she wont listen ive told her that, ive told her how much her freinds and family would be hurt if she di d it. ive gone over everything she just keeps refusing to beleive anyone does care

I dunno, I'm scared that she might do something stupid while she is upset. I don't want to lose her. She is a strong girl but she is very sensitive with her emotions and stuff. I hate seeing her like this. Have any idea how to cheer her up or something? I've done everything I can do.