My heart hurts for you. I know it doesn't ease your pain to know that, but you're not alone. I'm sorry you're going through this. I wish I knew what to tell you for advice. The only thing I can think is her bringing up the fact that she doesn't trust a lasting change in you. I'm not sure it's a DB technique, but is sitting down with her and frankly, without emotion, discussing a trial separation where you "prove" your changes a possibility?