First of all I am so, so sorry. How traumatic this must all have been for all of you. My heart just aches.
Second, I am still really worried about you and your safety. What are your plans? You are going to press charges against him, right? Are you going to get a restraining order, and call the whole marriage quits? Or are you going to let him do a one week stint in rehab, and take it from there? How many times has he been violent with difficult child 1, twice now, right?
I guess I am just worried about you getting anywhere near him ever again. Usually once physical abuse starts, it never stops, but instead it gets worse. Please call a local domestic abuse line, so that they can give you more information on this sort of thing -and please, please take care of yourself. I am sending you big strong hugs - and know that your cyber family cares about you.