I see why your concerned, there isn't just one or two tiny things that are not the same, pretty much everything is not the same.
It could be due to such long alcohol abuse, they always say the next time you go out can be your last; and that goes farther then death..you might just never bounce back from any damage done to the brain. Sometimes that one more relapse can just push something over the edge that was on the cusp before.
I am a recovered heroin addict, but I went through years of being put on different antidepressants and no matter what the dosage or which medicine they never worked; I'd get super ansy, I'd get angry, I'd give up because I just felt horrible. I have finally been properly diagnosed with bipolar type 2 disorder and have finally gotten the medicines that I need. With bipolar you have to be very careful with SSRIS because they can send the person into manic states or extremely depressed states.
If at all possible a full psychological evaluation (takes between 1-2 hours) by a psychiatrist that specializes in addiction would be my first step to see if there are any undiagnosed mental health issues looming.
Make sure to pay attention that his change doesn't start to turn violent, for the safety of you and your children I would stay aware for any slight changes in that direction. It is infuriating when doctors won't truly listen, but just like you cannot control what he says, does, thinks, or how he acts..you can't make a doctor take you seriously if they are not willing to listen. Second and third opinion would be ideal but if he is not willing you cannot do anything about that.
Maybe it is time to start thinking what you are willing to put up with and where you will draw the line if things continue to get worse. Are you staying no matter what the situation becomes, or are you going to set boundaries that once crossed are a deal breaker and you leave with your children? It is good to have a plan, even if you don't think you will need it it is still better to have one in place because when things start to really hit the fan it is hard to think clearly so doing the thinking now will help a lot if the time were to come.