Therapy for both of you would be good. I ended up going to counseling (am still going) to learn how to live with my husband who has some issues he's not ready to deal with - it's given me an outlet and ways to handle things when things get tough.
I think Purplebutterfly may have hit on something too - the postpartum depression - I've had it too and it affects every aspect of life, not just the baby part. Maybe if you approach your wife with "one thing at a time". If she/you do want another child, she needs to get stronger (I read somewhere that it takes a woman's body up to a year to "recuperate" from having a baby). In that year's time, the two of you can go to therapy, she can resume her medication (the kind Purplebutterfly was referring to) and then maybe think about another child after she's had some time to settle in to the new surroundings.
It is hard, people here know - you've come to the right place.
Einna