S.Z.
Men tend to be overwhelmed by fatherhood, especially first time fatherhood, but they are no good at saying, "I'm overwhelmed." Men tend to feel that admitting they can't handle everything means they're weak or incompetent. (They also tend to feel that something isn't real unless you say it out loud.) They feel very deeply the responsibility of being responsible for another life, and it freaks them out. They'll be panicked about how to pay for college while their wife is concentrating on getting through teething. Directing anxiety toward the baby feels wrong, so they direct it toward their wife.
They often also feel overwhelmed by talking to their wives, since men and women speak and think so differently. The fact that women can put things into words so easily and they can't leaves them feeling like they're struggling and will never "win," a concept that is lost on most women. We think in terms of understanding each other, while men are always thinking in terms of position - who's in charge, who's winning. When they start feeling, even unconciously, that their wife is "in charge," they start looking for places and situations where they feel that they'll be top dog.
On top of that, they are often freaked out about having sex with a mom. Most men spend their lives thinking of moms as completely non-sexual beings, and the idea of having sex with his daughter's mother might make him feel uncomfortable. Or, he could still be thinking of you as the hot little number he dated, and you might feel differently now that you're a mother.
He doesn't want to hear your complaints about work because men feel compelled to fix things, and he hears your complaints as a request to fix something he has no control over. This, again, seems foreign to women, but to men the idea of having someone listen and say, "Oh, I understand, that must be so hard" is foreign. They cannot imagine why that would make you feel better, or why you would bring anything up if you don't need or want him to fix it. Being unable to fix your work problems makes your husband feel helpless, and feeling helpless makes him angry.
He's looking to find something in his life that makes him feel totally on top of things, in charge, and admired. He needs something besides his home life because most men are terrified that they will (or are) failing their wife and children. When you tell him how overwhelmed you are, he worries that his family is falling apart (and that it's his fault.)
It might really help you both to get some counseling or take some classes in communication, so you can each really understand the other. It also helps to get 3rd party input.
Relax a little, and don't ask him to explain with words what he's thinking or doing. Watching how he behaves will give you a better idea. Praise him whenever you can! Men need a lot of ego boosting. Walk away from any arguments you really don't want to have. Be a little more available or take a little more initiative romantically than you might otherwise (even if you're not really in the mood - it'll make your husband feel loved and manly.)And make sure you two have those once a week date nights!!!!! That will do wonders.
Good luck! This too will pass.