Okay, confession time here. I as a supporter have done the same thing as your husband is doing to you (Not anymore . . . Thankfully). But let me enlighten you as to why. Suddenly without warning there would be a shift in his behavior. It could be aggression, irritability, avoidance or whatever and we have been through so much with PTSD that the smallest thing would put me on high alert and I would watch every facial expression, sigh etc. due to fear and insecurity. I would also worry about him and knew that he was in an avoidance episode and he wasn't going to fully communicate with me.
As a supporter this can be very confusing and intimidating. We aren't given a manual on PTSD. It's trial and error. It's hard not to take things personally and if he's ever experience you in a major depression, then it makes it even harder to give the sufferer that space they desperately need due to fear.
I finally got into therapy myself and it has helped me tremendously. I have overcome a lot of bad habits that triggered my husband when all I wanted to do was help him. But my intention was never to frustrate him, trigger him or not give him time to heal. We just don't know what to do sometimes and damnit when we make the wrong choices with the best of intentions. It's hard!