I can understand that you feel terrible about the conversation, but she is still in the tunnel and evidently she felt safe in talking to you. At the moment, that is how she feels, Today? Well, that could be a different story. The fluctuate between being unhappy and being happy. Do not take what she told you personally. If there is a dart of truth in what she said, then you have something to work on. If you know that what she said isn't true, then shake it off.
Continue as you have been. There are going to be moments of this type of talk because she is still trying to figure out why she feels the way that she does. Depression takes time to work through.
Please, please do not allow her talk w/you take you down in the rabbit hole.
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.
