My daughter had a similar situation with her boyfriend. He teaches classes and tutors all day long in addition to going to class. She mostly works from at home, and is working on her thesis, and is by herself most of the day. When he comes home, the last thing he wants to do is socialize. She, on the other hand, has been by herself most of the day, and wants to be around people, socialize with either his or her flat mates, go out with friends, etc. He just wants to chill out by himself, maybe spend time with just her, alone. It actually took some time with a counselor to get her to see what was going on, that he wasn’t being mean or antisocial. He’s started letting her know if he’s exceptionally tired before he comes home, and she gives him space, either by making different plans so he can have some alone time, or not expecting him to want to hang out with people. He, on the other hand, compromises sometimes and goes out or is deliberately nice to people when he would rather have quiet. It balances.
When you have a child, you become someone’s mom, and it’s easy to lose your sense of self and your own interests in the face of that, especially when you stay home all day with a small child. It’s one of those funny things, it’s great to be able to do, but it’s also hard to be able to do, unless you have lots of friends who are also stay at home moms. When I was at home with mine, I was the only person in my neighborhood that did not leave for work in morning. There was no one in the park during the day, except for groups from day care centers. I had no one to talk to; my friends from my old job only wanted to talk work.