Do you have a job?
Is he helping you financially?
Yea, he probably did/does feel like he lost your party friend when you took your pregnancy seriously. You were sort of forced to since you were carrying the baby. He however had on restrictions and apparently was too self-centered to start changing his life for his child.
Was this baby planned?
It sounds like he might be having a change of heart and is slowly coming around. I’m not sure but him hanging around and helping you might mean that. You could give it a deadline, like maybe 3 months. If he does not come around in that time, then you know he’s not going to.
An alternative way to handle this is for you to sit down with him and have a good talk, tell him that if he’s going to be hanging around your home, he needs to be 100% into the marriage and family.
A lot of men feel like a 3rd wheel in pregnancy and after a baby is born because their wife’s attention turns to her condition and then to her baby. I’ve heard it described as she falls in love with the baby and so has no time for him. Did this happen with you? I think from what you said, it felt like that to him since you stopped being his party buddy. But did it go even further than that? Did you push him to the side?
If the two of you are going to stay married, your marriage needs to be completely re-negotiated. You cannot be his party buddy all the time. Nor can he be yours. You BOTH have a baby to raise. I’m sure that right now he sees the baby as your job to raise and he’s the outsider.
There are some good books that might help you. “The Proper Care and Feeding of Husbands”
It is extremely important that your marriage be the center, and most important, relationship in your little family. Without the foundation of your marriage, it leaves you child in an unstable family. You baby will grow up and one day leave. If you are still married, you will be left with your husband. So, nurture your marriage first. Then the two of you nurture/care-for you baby.
Two other good books are “Love Busters” and “His Needs, Her Needs”. There are links below in my signature block. You can read both books. Then if he agrees to work on your marriage, as him to read them with you and do the work they say to do.