Suicide

I and a girl are in relation from January this year. Things looked good the first month but from next month her complaint of me changing came. I tried explaining her but in vain. She stopped understanding me and keeps crying. I have done everything possible to make her understand my problems. I am looking for job and not having father,I also have to take care of my family problems. She now acts suicidal and keeps threatening me that she will commit suicide. She keeps telling that she is getting suicidal thoughts. I have numerous audio recording of hers where she kept saying that she will die and I kept pleading her not to do so. I also called her brother and sister to make them aware of her situation but they talked very rudely to me and said that they will do nothing. I have audio recording of my talk with brother and sister too. Unable to take her blackmailing i asked her to write a note where she mentioned that neither me nor her family is responsible if anything happens to her. Even after all this,I still try everything possible to make her understand what would happen to her family if she does so. I ask her to concentrate on career but she only wants me. What should i do now?