Would It Be My Fault If My Friend Commits Suicide?

I became friend with this girl named Laura over a year ago. When I befriended her, I didn't realize that she had so many problems. I decided to take her to a movie since she seemed lonely and depressed. Then I didn't talk to for about a month or so. Then I got a call from her that she was in the mental hospital for swallowing pills. Something about missing her brother because he died along time ago. So I visited her in the mental hospital and brought flowers and an inspirational book. I felt kind of guilty because I didn't know her condition was that bad and thought that maybe I should have done more than just take her to a movie one time. When she got out of the hospital, we continued to be friends. We did alot together. I spent a lot of time and money on making her feel special. I even took her to see an aroma therapist. However, I just can't deal with her anymore. She is constantly negative, no matter how hard I've tried to correct her thoughts, she's still negative. She constantly talks about the following things: Fears of being a tramp, fears of being a , fears of becoming a offender, fears of going to hell, fears of someone sneaking in her room and sterilizing her in the middle of the night, her boyfriend not loving her, someone abusing her and not being able to remember it, fears of being fat, the voices in her head taunting her, fears of committing suicide, on and on and on. I've got my own major problem right now. My boyfriend d me and I'm 9 months pregnant. My baby is going to be born this monday and he is being adopted. So, I am not going to be in the mood to put up with my insane friend anymore because I'm going through my own crisis. I'm going to be dealing with parting with my baby boy and can't be a support to someone like her anymore. My adoption councelor told me that if I'm staying friends with her because I'm afraid of her committing suicide, then it is co-dependent. So I tried ignoring her phone calls for a while. But then upon listening to her voice messages, I felt guilty and bought her a gift and visited. When I got there I found out that she was contemplating suicide because she did not get the job that she wanted. Even though she doesn't need the money because she's on Social Security, but it made her feel like a loser that she didn't get a job. I don't know what to do, ignoring her just makes her think that I'm mad at her. But I can't continue this friendship anymore specifically with my baby situation. How do I break this off? I've tried introducing her to a couple of my other friends so she'd have someone else to talk to but it hasn't worked out. Every time she meets one of my friends, the first thing she tells them is that she swallowed pills in the past. Please give me some advice. Thanks