When you care about someone and they keep hurting themself, that's really hard to deal with. I think you recognize that the pressure got to be too much for her. She has to take care of herself and it sounds like that means getting out of the relationship. Sorry.

You need to take care of yourself too, and nobody can help you unless you are helping yourself. When other people care more about you than you do, and work harder to get you better than you do, it doesn't work and they get frustrated and even if they love you and care about you, they will eventually give up because you keep rejecting their help. It isn't enough to feel bad about it - you have to work on getting better, and not overdose again.
I hope I haven't been too blunt, but that's the way I see it, so I'm being honest with you. Yes, it's hard. If you want to hang around here you will find people who can understand what you are going through because a lot of us have been there too. We can provide some sympathy and encouragement. Still, I hope you are ready to work on your problems and try to get better. (You are seeing someone professional, I hope?) I'd like to help you, but nobody can unless you are willing to help yourself.
Take Care
<font color=green>"Loneliness does not come from having no people about one, but from being unable to communicate the things that seem important to oneself, or from holding certain views which others find inadmissible" Carl Jung</font color=green>
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“We should always pray for help, but we should always listen for inspiration and impression to proceed in ways different from those we may have thought of.”
– John H. Groberg