You didn't "push her to the brink"--she's already over the brink.
Since she asked you not to contact her again, I'd leave her alone. If she does contact you, you can apologize for any cruelty in what you said, but I wouldn't go further than that. You can say you are sorry for any hurt you caused, that you hope she chooses recovery at some point, and wish her well. Under NO circumstances should you get involved with her again--not unless you want a whole bunch of avoidable misery in your life.