I was going to respond to this - but @Friday did it way more eloquently than I could have.Surely PTSD wouldn't do that?
I'm so sorry you are feeling this pain. Your responses here show that "what did I do" instinct that I feel every damn time. It's like a rush of adrenaline, heat, through my body. Leading to the inevitable questioning of myself. It's like I have to talk myself down off the ledge and remind myself constantly that it's not me, it's him, it's the ptsd.
You are being incredibly brave and are doing the right thing. You have said what you feel and you are resisting the urge to reach out, you're sticking to your convictions.
What will you do if he does reach out again, have you thought that through?