It wasn't overnight, all of your problems were always there. The childhood traumata, PTSD, Alcoholism, bad coping with stress. Add losing his job(s) and more alcohol and the situation exacerbates and spirals out of control.
Exactly. It's plain to see in your 2 or 3 paragraph summary of your life that there were red flags all over the place before you got married, you chose to disregard the red flags (most of us do), you got married anyway and you ignored the problems as they gradually got worse until it totally blew up on you.
Even though things are relatively quiet at the moment, given the history and all the factors in play and the lack of proper treatment, there's a high likelihood that it's going to happen again.
Some have suggested divorce, yet you "don't want to go through it again". Well, if you didn't want to get divorced again, then you shouldn't have gotten married again. The odds are poor for subsequent marriages, even without all the cheating, and the alcohol abuse.
I'm sorry but it's only a matter of time, you're better off cutting your losses now, rather than later, you'll have that much more time to rebuild your life.
And stop getting married.