I've delayed responding to this thread because I have been where you are and I have been doing very well and quite frankly, didn't want to go back to those memories. My xah, white-knuckled sobriety for 1 year after he proposed, until a month before the wedding so he could "participate" in bachelor parties and the other "normal" activities that go along with a wedding. I found out much later, he hadn't actually quit drinking all together, just became better at hiding it, which is it's own kind of hurt. As well, as smoking weed and prescription abuse to "help" with his lack of alcohol consumption.
I ignored all the red flags and believed he would out grow it or change and couldn't look forward enough to see how difficult the future would be. Married to an addict, two little kids and a decade later I was a shell of my former vibrant, confident self. My life completely evolved around what he was doing or not doing, who he was with, where he was, etc.
I've been out for some years, life is good. We have no contact with the xah. The pain of staying became greater than the pain of leaving him. I don't know if I would have reached out first and gotten the same (amazing and spot-on) responses you have here that I would have ended the relationship or not. I was in my own bubble and never asked for advice or help.
I guess all that to say, in my experience, I would always try to make a big deal about "if he would just not drink, things would be better ... " eventually I had to accept that he was showing me who he really was. If it wasn't alcohol it would be something else. Always. Before me. Before the kids. Before everything.
Wishing you the best in your decision.