Hi subjugated. Welcome to SR.
(I really hope that in time, you change your screen name...I did, and it was very liberating!).
Reading your post felt like reading one of my diary entries from when I was married to my XAH. I did the same things you did: bargaining, reasoning, threatening, attempting to control the drinking, pleading, raging. My life was a total rollercoaster.
I hope you can see that what you've been doing so far hasn't worked. This is where the 3 C's of addiction (whether to drink or to gambling or drugs) come in handy:
You didn't CAUSE it
You can't CURE it
You can't CONTROL it.
From reading your post, it seems you're already detached but you also seem terribly unhappy. I know you're concerned about "breaking up the family", but have you considered that due to your H's drinking/gambling, it's already broken? Your children already live with two very unhappy parents. Don't they deserve at least ONE happy and healthy parent? And don't *you* deserve to live in a peaceful, sane home?
There's honestly no perfect time to leave. It's when you are ready. I would however encourage you to consider what effect your current family life is having on your young children.
I too agonized about not giving my DD an intact family. I felt guilty that I'd be the one walking out...my XAH would never leave, no matter how unhappy he felt. He would want to continue being the victim. Eventually though, it dawned on me to imagine my DD, grown up, living the life I was living with an addicted and abusive husband. I realized that everyday, I was modelling an unhealthy relationship for her and she'd grow up knowing nothing else. That's honestly what pushed me to leave.
Keep reading and posting...SR is a great place to be!