It’s like he wanted all the rewards of a relationship but not the work that goes into any committed relationship.
I’m sorry you are experiencing this loss of him, but it’s true your kids need you.
Try not to beat yourself up for wanting more with him, or asking more of him. This relationship was going to end eventually, no matter what (my opinion). He’s “great” on a superficial level. I can’t understand his insides, but he has all the power. Don’t let him take your power. It was a lovely arrangement it seems, but it was on his terms.
You deserve commitment.