Hi Gracey,
It doesn't sound like your heart is turning cold. Just sounds like you are taking care of yourself (and your kids) and recognizing your feelings instead of worrying about his all the time. Sounds a lot like my AH. It is almost like he expects me to be more like his parent than his wife. For goodness sake, he is an adult and I've already got three kids that need me to be their mommy. I'm with you, I enjoy the time when he is not home. Sounds like progress to me.
justired