Lunar I didn't say he should be allowed to sleep all day! I suggested waking him up mid-morning. If he's too hungover to safely look after baby, he can do laundry/housework instead then take over to let OP sleep.
Don't underestimate the need for time away from baby. Even if DH just takes him out for a day so you can sleep. I wasn't suggesting a spa-day flippantly, I didn't want one until DH booked it. The joy of a few hours in a hot tub, jacuzzi and being massaged was indescribable. I went with my best friend. I was too shattered to talk much so we just sat in silence enjoying the quiet. Just being out of the house, out of earshot of the screaming, and not covered in baby-sick, in the company of a sympathetic friend, was enough to change my whole outlook.
However, I do think your DH was being selfish to drink heavily when he needs to be on duty the next day. If mine did this I would insist he takes baby out for the whole afternoon so I can get 4-5 hours sleep.
I don't think it's worth falling out over though. The last thing you want on top of everything is a huge row.
As for mat-leave, why are you doing all the housework, ironing etc? I didn't enjoy the first few months, it was more survival. But I did feel sorry for my DH, as he was stuck in an office in a high-stress job then commuting 2hours home, then helping with baby and suffering broken nights etc. Whereas I could pop baby in sling and go out all day in the fresh air, in the company of friends who understood how hard it was.