Oh Maggie! It sounds like he was doing so well on meds! I just hurt for you thinking about how disappointing this is for you.
They do follow patterns, yes, if he has been violent before, you know it will go that way again. Yes, the holes in the wall might show its starting up. You should call the police at the slightest threat. Verbally threatening to hurt you, looking at you and hitting something else, anything like that. Yes, keep the dog with you.
Does your county have a mental health officer or Crisis Intervention Team? They prefer to be called out to help before it gets violent.
Beside the walls, what else is happening when you say, “its already bad”?