To the moms of young ones... Really to everything there is a season. It will get better. I would encourage you to continue to carve out some niche of learning or intellectual engagement. It doesn't have to be an all or nothing thing in your life, but it is really a good and healthy thing for kids to see that mom has something else to focus on besides them. Even if it is "just a minute until I finish knitting this row" or "I'll help you as soon as I finish this page" it is not a bad thing for kids to see you model being an engaged person who is learning something new.

Also, I think it is reasonable to start to think of an end point. Where I get concerned is when the sole focus on kids drags into the preteen and teen years. If mom feels she can't focus on anything else, ever, that is not sustainable or healthy. At a certain point that can feel like a burden for a kid too. How is a child supposed to process that they are such a burden that mom can no longer even think of herself for a minute?