There's a possibility that perhaps he is genuinely sorry for the way he treated you, and he is trying to do the right thing by apologising? Who knows. If this is the case, now that he's done that, I wouldn't really expect you to hear any more from him? If he does continue to contact you, then I'd be questioning his intentions.
It's all well and good to say he has PTSD, but that he's done with therapy. I can't say that's a positive thing? At the end of the day, you've moved on now, and I think you need to keep heading in the right direction for you. That may mean deleting him off your friends list on Facebook and perhaps ignoring phone calls and texts until he gets the message. I think it's important that you make it very clear to him that things are over, if you get the impression that he's wanting to re-establish a connection with you.