You need a non-tech hobby. Family is perfect for that. Whatever your previous hobby was, it's with family now. Travel with family. Watch horror movies with family. Play tabletop games with family. Watch YouTube in bed, with the baby under your armpit.
Then you need a tech hobby. Find something interesting to do. My kids draw, my wife cooks, sometimes the kids play with each other and daydream. That's a great time to mess around with new tech and algorithms. I've learned cheap, fast website hosting, SEO, procedural generation in my own time in the past month.
Also don't learn for the sake of advancing your career. Learn to be able to build interesting things. Find an interesting problem to tackle, something with possibly no economic benefit, then learn how to do it best. This will actually advance your career better than trying to learn the next stack. Like make CSS art, or do something like writing your own voice autotuner.