he's probably off on what is known as a "spinner" - multiple days of getting high. i believe you said he's a meth user? that can go on for days 3, 4, 5, til the body just crashes. then he'll crawl home filthy, unwashed, body depleted of any vitality, filled instead with poison, and sleep for a good 16-18 hours, then wake up starving. and in a really REALLY miserable mood.
you get to choose how much longer he gets to parade in and out like this. you HAVE the power to change, just not HIM. sounds like he put on the well behaved act, did the things that husbands and fathers do for the shortest time possible, all the while just itching to get to that next hit. such is life as a meth head.