Hey, Bud.
I lived almost exactly this. Three kids, no romance, no sex, no joy. Just business partners running a household.
It finally came to a head when I was driving and the song Self Esteem by The Offspring came on, and I just broke down. Even if you're familiar with it, go ahead and give it a listen.
After being together for 15 years, I filed for divorce. The entire process was very emotionally challenging, but it was amicable enough that we didn't need to involve lawyers. We split custody 50/50 a week on and a week off. (Although, I don't think it works as well as we expected. The kids get lost in the shuffle, and next week's problems just become the other parents problems. I'm starting to think the kids don't have as much stability as they need.)
That was in 2018. I'm remarried now, with two stepsons in addition to my original three kids. Things are much better now, and my only regret is waiting so long to do something about it.
Go find love! It's worth much more than all of the reasons you've convinced yourself to stay together. You deserve it!
I wish the best. Stop throwing away your life for someone who doesn't even care about you!