Hi, My Friend Is Going Through A Break With This

Hi, my friend is going through a break with this guy that she keeps dating. It's been a cycle and they break up and get back together constantly. This time she is more upset than usual and is cutting herself and saying that she wants to kill herself. I know she wouldn't kill herself but I'm just not sure how to help her. She has seen counselors in the past before I knew her and she says they didn't help. I'm worried if I tell her parents about her cutting she won't forgive me. What should I do to help her?