Damn. I need a drink after reading this. I'm sorry you're going through this. I do not regret my divorce, but I also didn't have kids to raise. I got divorced because I was going through my spiritual awakening aka mid-life crisis for some. My ex-husband did not understand anything I was going through at all and honestly, I needed to get back to me.
I know it's cliche, but look at the upside whenever you can and look for the tiny little good things that pop up from time to time, like the kids are healthy, you found a twenty in your pocket, or got a tax refund/break this year.
P.S. I hope you're doing okay and getting paid through publishing on Medium. Best wishes <3