I hate when threads jump to "it's abuse", mostly due to stubbornness surrounding my own relationship with a PTSD sufferer. Some with PTSD isolate (flight), some lash out (fight). With that being said, there are children involved here and based on their questions, they are obviously aware. I think it is time for you to take concrete action until your husband is better able to control his behavior and reactions, while knowing that he's not going to get better unless he is the one that starts wanting to make a change. I also especially think that he should be the one that has to leave and go cool off somewhere else when upset or want to be done, not you and the kids. At this point, the kids definitely need to be priority here.