So his wife has some condition and he is left to do "women's chores". That's it. He's uncapable of channeling his frustrations, doesn't even understand.
You have a small baby, sleep schedules are all over the place, pitching in isn't some chore you do just while she's out of commission, there's a human to bring up to adulthood.
The author is clearly not in a good place. Ours firstborn was really difficult too, the lack of good sleep and free time can really wear you down.