Now that I've got a minute to really respond, this is a beautiful story. I remember I used to rush over to my sister's house after her youngest was born so I could bottle-feed him. I felt absolutely drunk afterwards. One day, I started wondering why I felt such intense emotions and I remembered reading something about how bottle-feeding can also be as emotionally bonding as breastfeeding. It gave me a glimpse into what that connection feels like and just from the little I know, it is something hard to put into words.
And your description of the way sex played a role in your marriage and the way those emotional/hormonal connections played a shadowy role in an already difficult situation...damn, you described that so well. <3