Well, i can certainly relate. My children are 16 and 12 now but i remember how my husband behaved at first. I often said that if i could go back, i would have treated that behavior differently. I am older and wiser now, and know my husband alot better. Please forgive me if any of the advice I give seems obvious or doesnt suit you, as i dont know how your relationship goes :)
If I could go back, i would be more sympathetic to my husband. I did not realize all of the stress having a baby puts on a man who is taking it seriously. They worry as much as we do! Just in a different way. I didnt realize that then. I would treat him as I want to be treated. Giving him hugs and asking if he had any worries and telling him how proud I am that he has a good job and can provide for our family and taht he was going to be such a wonderful father etc. I just didnt see his point of view. I also didnt realize how consuming the "baby talk" was. My husband felt as if our life just watching tv and talking about other things INSTANTLY went away and thats all we talked about all of the sudden. That made him feel very lonely. Weird huh?Your sweet hubby is probably going out and staying out not only to try to escape from this new responsibility but to cope with it as well.
THAT BEING SAID....
Leaving you alone until 2 am is unacceptable if you are feeling lonely. Say these words, however cheesy and weird they sound.
"Honey (or whatever you call him), do you want to talk about any worries you have about the baby? .......(wait for response.....listen, dont criticize, just as you would want him to do for you) Is there anything I can do to help you? (be reasonable if he has suggestions)"
THEN maybe at another time say
" Babe ( or whatever you call him) Ive been really missing you lately, especially when you are out so late. (try to be understanding and not demanding if he is defensive) I just wanted to let you know how I am feeling and that I miss you. It would be wonderful if you decided not to stay over there so late and as often" Then leave it at that. It will be hard, but try.
Seek other friends of your own to chat it up about the baby 24/7. You dont have to not ever talk about baby stuff, your hubby will have to figure out how to cope eventually. But try to just "BE" with hubby as normal some of the time too.
Anyway, thats what I would have done if I could go back. That approach works much better for me now. Requests not demands, Understanding not criticism. Thinking of his feelings TOO not just my own or INSTEAD of my own. Giving him a little space at first and then letting him chew on it usually gets me the results I want.
I am sorry you are feeling lonely. Motherhood can be a lonely business, but not to worry! It is also sprinkled with wonder, delight and much accomplishment. And lots and lots of love. You just keep dishing it out.
Good luck to you.