I remembered your thread when I saw the title, and thought - 'oh God I hope that's an update to say she's left him.'
Ok, first thing to say is that you now know you need to leave him, but can't see you doing it before the baby is born. As someone who has gone through the newborn stage twice, can I please please beg you to reconsider. Please.
It's a given that he will carry on drinking, and so best case scenario is that in a few weeks time you will be facing the same situation as this morning but with a baby to care for. There will be nothing so hopelessly lonely and depressing and hard in the world as that, which goes double if there is any issue with the baby- difficulties feeding, colic, even general perfectly normal hard, non-sleeping early days stuff. How, just how will you handle this when it's 10am and he's AWOL - but the difference between then and today is that you've had two hours sleep and have a crying baby in your arms that you desperately need taking from you just for a minute's rest?
The chances of you not coping, possibly developing PND, or simply just having the early days with your baby comprehensively RUINED are, I think, significantly higher if you choose to cope with that situation than the other, still very difficult option of leaving him now and doing the newborn days elsewhere.
Can you go to your sister? Seriously, could she put you up for the first couple of months? It's a huge ask, but think about it?
Secondly, do you want to say where you are? There are folk on here - me included, with all the normal caveats of sussing someone out before accepting help in RL - who would be happy to offer practical support.
Thirdly and very importantly right now, you NEED to plan backup for the birth. Again, how far are you from your sister? Please try and minimise the stress around the birth planning by telling her exactly what's going on and discussing a plan for her attending. At least then you might feel a bit more in control.
The thing I think is most disgustng - and pitiful - about this guy is the utter, bare-faced refusal - so arrogant, really - to face reality. He's pushed and pushed his version of the person he'd idly like to be, but actually has no motivation whatsoever to become, in your face so hard that you've had no strength to do anything but accept it. But in reality he's an aggressive, unintelligent, uncontrolled boor. As you've got further and further into the pregnancy and he's seen you get more tired, less able to focus on external stuff (you describe letting go of Al-Anon and turning a blind eye to his drinking as a failure, but it's not - you're simply more pregnant and thus less able to take on stuff like this, you automatically go into head-down mode) he's relaxed, started strutting again, dropped the pretence.
And do you've gone from the whining, pleading ''I'll be the best role model and best daddy, I'm for real this time, I won't let you down' PIGSHIT to you worrying that he might be too drink to be at the birth and he says 'Yeah'.
He's an utter scumbag.
Look, this morning, call your sister, tell her everything. The aggression. The promises. The whole lot. Ask her to be ready to be at the birth and tell her that you are leaving him. Soon. And see what she says.