PTSD question, for anyone familiar with it?

My husband came home from Iraq in 2005 a totally different person. After two years of begging him to go, he went to a doctor and was diagnosed with PTSD. (I should note, he went through 3 doctors before any of them did anything but shove drugs down his throat and ume he was better). During that time he would get stressed out over something that didn't seem to be a big deal to me, then fly into a rage. He would say terrible, mean things, call me names, and break inanimate objects. Through research, I found that this is not so unusual. With treatment, his temper got better. Lately he seems to be trying really hard to repair the damage that has been done to his marriage. But over the past week or so, things have changed somewhat. He seems kind of out of it. Gets confused easily, seems to zone in and out (half the time I feel like he has no idea what is going on around him) and spends a large amount of time sitting on the couch, just staring at the walls. I know that this is not unusual behavior for someone with PTSD, but it worries me that his behavior has changed so suddenly. Should I be worried about this? I suppose I should also note that I suspect (but admittedly have no proof) that he has not been going to therapy for about a month.