Ok, musings of a busy brain this morning...
I wonder if the first step in this is forgiveness? From my own perspective, I see where holding onto the past hurts creates a distrust and also resentment on the part of my SO. Basically, the message I hear is "I didn't do this, why do you take it out on me?". That is a very valid question and the feelings associated with it are valid.
At the same time, I feel intense guilt for the hurt that I inflicted. I have apologized and any decent person does not go out of their way to deliberately inflict pain upon another. Sufferer's are especially aware to the damage that abuse can do, and for me, my greatest fear was inflicting abuse upon someone else. That was why I isolated and withdrew. I think at some level we all know that we are not "safe" during certain periods of time and we push away those we love. This act itself causes great hurt, but also not removing ourselves can create emotionally instability that has the potential to hurt those we love.
Ultimately a sufferer's primary responsibility is to get as well as they can. Not only does that benefit them, but it benefits everyone around them. We all get that and that is what we all work on. But for me to really heal and move forward, I need to know that I am forgiven and accepted for who I am. That does not mean that I have a free pass to let PTSD fly and that is absolutely unacceptable. But I cannot change the past and when a person is unforgiven, it feels as though the past is hanging over their head like some giant scorecard and someone is making tick marks for every little slight.
But those are my thoughts and feelings. What may look like "unforgiveness" may be self-protection. Withdrawal is a self-protective mechanism used universally. That is another problem, what is happening and what part does personalization and generalization play into the thinking and behavior?