Lynette.
I love SGB's ability to inject some humour into serious posts without actually detracting from the issue at hand, which is, of course, exactly what I'm doing now by hijacking this post. Sorry.
I was thinking about this post over my last coffee and it occurs to me that there is more going on in this relationship than simply readjusting to life after a baby (though that's a huge thing in itself). I find the comment: "I am hoping that he will see that he is being ridiculous or will admit that he doesn't want to do the family thing and just leave" quite telling. Sue, it sounds to me as though you're completely emotionally exhausted and have already started withdrawing from the relationship emotionally. Speaking from experience (two failed relationships), I know that once I reached the stage where I started to see splitting up as a viable option, rather than trying to see ways past the problem, I was already half-way out of the door. You are clearly quite close to giving up on this relationship, even if you're not ready to come out and say that just yet. Does your DH know how unhappy you've become and how serious thing have got? Perhaps if he did, he might be willing to compromise a bit more. If not, then that brings a whole new set of problems, I'm afraid.
Before children, I was a bit of a party animal - all-night raves, gigs, lots of alcohol and occasional recreational drugs. I gave it all up when we started to try for a baby. I don't miss the drugs at all, and I'm quite happy with the occasional drink I have now, but there are times when I would love to go out for a really good night out. I didn't want to in the first 18 months after my twins were born, but that urge is resurfacing now. I'm older and wiser now, with different goals in life, so I will never go back to certain things I used to do (like drugs), but some things still appeal. I think SGB hits the nail on the head when she says "if you enjoyed your happy hedonism in the past, that side of you will reawaken in a year or two once you are caught up on sleep". It may not feel like it now, but this early stage goes past so quickly.
That said, I also agree with MrsMattie: "Things will not be getting 'back to normal' ever again. Not unless he wants to shun responsible parenting for life as a sad old git who prizes boozing and shagging above his kids." Life DOES change when you have children. You simply cannot live life as footloose and fancy-free as you did. That doesn't mean you have to give up on a social life, however. You can still go out separately and have a good time (as long as it doesn't affect your parenting for more than a good lie-in the following morning), and if you can get a good babysitter, there's no reason why you can't go out together and do the things you used to. You just won't be able to do it as often as before. What isn't realistic, though, is for your DH to think it is perfectly acceptable for him to go out 3-5 times a week (), while you stay in bogged down in all the childcare and domestic stuff, and then wonder why you're not up for swinging on the weekend. He needs to start pulling his weight about the house now!!! If he does his fair share and then still wants to party, fair enough. You might even find you want to too once you're not shouldering so much. Or, he might want to do it less in favour of a takeaway, DVD and early night. At the moment though, he has all the fun of fatherhood without any of the responsibility and that's not fair. If he won't move on this issue, you've got serious problems. I am disturbed that he uses the excuse that it's "too hard" for him to pull his weight with the little one. That sounds incredibly selfish and, more alarmingly, that he seems to think his needs come before yours. That needs to change. Now.
Ultimately, only you know the ins and outs of your relationship and the personalities involved. I have a feeling that unless your DH meets you halfway, you are going to end this. With any luck, however, this might actually refocus him on what's important. I hope I'm wrong and that things work out between you though. A new baby puts a lot of strain on even the best of relationships, but people do get through it. Good luck!