When I was going through a breakup with the mother of my first child, our therapist asked us if you would be happier if the other was dead. Through all my muddled thinking, becuase a young child was involved, my answer was yes. Our constant arguing was poisonous to our child. For me, it took her throwing me out three times. the third time I did not come back.
I was studying A Course in Miracles throughout our time which talks about our illusions of others being our saviors, of completing ourselves. And when they don't we crucify them.
My outlook on relationships as I have gotten older and perhaps wiser is not one of romantic fulfillment, but of growth and releasing old ghosts. Nothing easy about them, if people want to grow.
Blessings on your decisions either way. You have children, yes? May you always speak kindly of each other, especially with your children.