Have you started to look for other work? It's not easy to throw a job search on top of everything else on your plate, but if it gives you some of your own life back, it could be well worthwhile.
I have a 3-year-old son, and it's been an interesting ride. This year was supposed to be more relaxing because we got into a better living situation, but then my wife was getting bored staying at home every day. So she got a really interesting job, but the job ended up being way more involved than either of us expected. So our schedules are pretty hectic, but it's worth it to see her mentally stimulated and avoiding the professional detachment that can come from stay-at-home-parenting.
I have some really interesting personal projects going, which have been affected by family stuff. I have responded by stretching out the timeframe on these projects. That is better than giving up these projects entirely, and it is way better than ignoring my family in order to finish the projects.
If you limit yourself to one or two kids, your kids will be grown up and out of the house in no time, and you'll never get that time back with them. "Out of the house" doesn't mean 18 and living somewhere else, it can mean 6 and in school most of the day, or 12 and in all kinds of activities all the time. Those early years are prime family time; I hope everyone is able to let themselves enjoy that period of life.