Know that it is possible to do it, lots of people do, and it doesn't require you to be superhuman!
Sounds like survivor bias. Doesn't seem like there's enough hours in the day.
Care to site some examples with testimonies from kids that feel like they're getting enough attention and care from their parent that's doing these things?
I started my first business before uni, and at uni I regularly worked 18h days and had people work from my room during the day. There was a lot of hard work at times. Maybe a difference was that I put off having kids until quite late, so while things weren't easy, I had a glimpse of stability and agreed with my partner that we could cope!
I do know that I'm not a superhero.
No two situations are the same, and mine is not quite the same as yours, but I certainly wonder at times how I made ends meet etc!
Being reflective and considering these things up front rather than just reacting after the evnt, as you are, does help too.