As wrong as it may have seemed, I think you reacted too quickly by unfriending her. People with depression get too involved with their life, the negativity of it and their unhappiness. She probably did forget you were raped, and she probably does feel terrible about it. When she was talking to that guy who raped you, who's to say she wasn't pretending to be polite? It's really hard to tell when someone's being legitimate or fake over a Facebook conversation. Or maybe she tried reaching out to all her friends and used him as the last resort, because she knew he was your rapist. She probably didn't want to burden you with her problems, and now she's probably thinking what a crappy person she is.

I'm sorry you were raped, and it's not something someone can ever get over, really. You need all the support you can get, and this girl seemed like she was one of those support systems. I suggest you talk to her about this, figure out what's going on with her. Maybe even arrange to visit her, because I think seeing someone face-to-face can always revive a friendship that seems to be falling apart.

I also hope you are getting help for your trauma, talking about it with a professional definitely helps. They can help you figure out ways to cope healthily and, as in this case, not lash out at people without knowing the whole story.

It completely makes sense for you to have lashed out at your friend. I'm not saying you are wrong and she is right. Nobody is right or wrong in this situation.