I had a huge email ready to send and I hit the wrong button and lost it so here goes again.
Your situation is not unlike many many people! You are not alone. He sounds depressed and maybe scared of the impending responsibility. I have a few suggestions.
*research men and how the respond to a baby coming. Maybe write down a list of things responsibilities you both can share when the baby arrives. Be specific...who will wake up with the baby in the night, feedings, who will prepare dinner every night, etc.
*Ask him how he is feeling about his life. Is he scared, unsure, anxious. What are his expectations for the future. What are his dreams and does he feel he cannot accomplish personal goals with a baby coming?
*you start a mommy support group. meetup.com or send out a flier to people in your area in the same situation. This helped me tremendously. you are all going through the same things and it helps to hear that from other mommies.
*you find a hobby that you can enjoy outside of marriage and family. (he does too as long as it doesn't take too much time away from the family time or involve late nights at the bar) I scrapbook and I'm so thankful it's a passion that fills me up. But you need to make it happen because no one will do it for you. Don't thing he'll come to you and say "honey, you have been working so hard raising our beautiful child and being such a wonderful mother, how about I take the baby for the day and you have a day with your girlfriends". Aint gonna happen. you need to take care of yourself. Once you realize that, you will be better off.
* create boundaries for yourself. Get the book called "Boundaries". don't be out there trying to be everything to everyone. It doesn't work believe me I've tried it. no one will ever truly appreciate it and return the favor. You will always come up broken hearted. figure out what you will say yes to and what you will say no to. I wish I would have learned this earlier in my life, I could've been so much happier.
I hope this helps.
J.