This is a great post. Firstly, do not apologize for anything. A lot of the advice we all give here is much easier said than done. I too feel like I owe my advisers an apology when I’m not strong enough to follow through, but none of us need feel that way. You are clearly being thoughtful and mindful, and I don’t think you are operating from a place of denial in any material way.
“Maybe I don't really love him all that much and am just frightened of what it will do to the children and of being on my own? Or I'm emotionally detached from him as my romantic partner but not detached from him as my H and father of my children in other ways?”
I’ve questioned this about myself many many times. It’s really hard to figure out what the difference is I think, for women who think of motherhood the way I think you and I both do.
Anyway, just wanted to chime in. I’m going to read your post again more in depth and comment again in a bit.