I have a friend who is suicidal too. To be blunt, she didn't have any friends (for valid reasons) and I took pity on her and tried to be a friend. She had so much anger in her, she curses at people unreasonably for one. One day I had enough and I told her off about the cursing. It worked with me. I talk to her on and off. So as time went by, I empathised with her and actually REALLY tried to help her. At first I tried talking sense into her, sending her materials to read or watch, listening and comforting her but honestly she was so addicted to her self pity. She would toy with me on and off. I would get a message from her saying she is feeling depressed etc and right after i reply, she would say something like "Hmm I wonder how does it feel like to jump. Bye." I try to help her and she would be like whatever. It became emotionally stressful for me, it's like emotional abuse.
I believe I was in the same situation you are in. Many times I wanted to tell her off, I wish I didn't try to help but I felt guilty because she was suicidal so I tried harder. I felt miserable every time I talk to her. Until one day I had enough cause it's like she knows no boundaries and I set things straight with her. I am still a little mad. I told her to stop playing games with me. It is up to her to take the extra mile, not me. It is HER life and NOT MINE. Same to you, it is HER life and NOT YOURS. You have to know when to draw the line. When she starts bringing you down with her, you need to know when to say enough is enough.
Like what the others have said, it IS abuse and bully. Sometimes you gotta fight fire with fire. Sometimes being complacent and sympathising too much can be dangerous for them. They take it for granted. Like what someone said here, she is manipulating you by dangling her conditions over your head. By being suicidal DOES NOT give someone a passport to do whatever they want to another person.
Set things straight with her. I'm not telling you to desert her and "leave her to die" but confront her about it and tell her you do not agree with all the aggression. I'm sorry it is such a long post but I am still a little emotional and mad about it. Idk if I have written this sound aptly but the window is so small to preview everything and edit so I'm gonna leave it as it is.
I wish you and your friend all the best. PM me if you want to talk. Cheers.