Hello AF girlfiriend,
I'm glad he is seeking therapy - this is a good sign that he wants to manage his PTSD. Yay! I have no doubt you are worried about him, it's hard not to worry about the ones we love. As women, we want to "fix" that pain they are feeling and when we are shut out we feel helpless. Helpless is a really hard feeling to deal with sometimes. Continue reading and asking questions - learn all you can about PTSD, not just the withdrawal. Take care of yourself - do nice things for you, go out to dinner with a girlfriend or something else you enjoy doing. Stay busy. He probably shut down because that nightmare caused a lot of stress in his mind and now his brain won't shut down. He just needs to find his center again and because of this he may not want outside stimulation. This outside stimulation includes you right now. He will call you or see you when he is ready again. I'm so sorry you are going through this - PTSD sucks.
Take care,
Sisu