Am sorry to say, but it sounds like she, although a little mixed up and mixed signals at first, sounds like she wants to move on. I think had she really wanted to save the relationship, she would've spoken up 6 months ago to talk about why she was unhappy, and not just leave. She has made no moves to try and sort things out, so I think that she's certain now. You could try talking one more time to see if worth saving? I wouldn't recommend pursuing too much, and if she says no again, I think you should take her word on it and try and move on.

Be kind to yourself, go see friends and do something you like to do, I know it hurts. Please don't take all the blame in this (and learn from your mistakes if you did indeed criticize too much). Relationships come to a natural end sometimes for one person and there's little that can be done about it. Am sorry.

Hugs