What is average partner involvement? And…what should I do about mine?

I have 3 kids. I spend 19 hours a day in the presence of one child or another. That’s 133 hours of “work hours” per week. How is this possible? You ask. Cosleeping with my infant. Exclusively breastfeeding round the clock. Homeschooling. Yes, I spend that much time with my kids. And those 5 hours that I have before I climb into bed with the infant is the only set time I have to clean/pick up/meal prep/do laundry and take care of myself. I honestly have no clue how moms of erratic sleeping kids do it. At least I can count on my older kids to sleep through the night. I used to be a writer. I’m still an author, for whatever small income it brings in a month. I need to publish another book. My mental health requires that I have another identity that isn’t just mom. But when do I write? A few nights ago I stayed up until 6 am to fit writing in before waking up with the kids at 8:30. It wasn’t as bad as I thought it would be. It’s good to know I’m that tough. My husband is an investor. He sits on his computer, sells stocks, games the market. He’s good at it. We’re well provided for. The problem is that his work takes 2 hours a day. And then he’s free. And when I ask for help he acts like I’m asking for the moon. “But I’m providing!” “I already spend more time with my kids than the average dad!” “You get 5 hours a night for yourself!” No, I don’t. I keep this house running. Keep you in clean underwear. He is living his dream of early retirement, and I’m staring down the loaded barrel of burnout. Love my kids, (of course) love my husband (maybe), but is it really too much to ask for 10 hours a week for writing? I don’t know. Maybe I’m being selfish.