"after explaining to my DH just how much I wanted the opportunity to carry the child, he came around rather quickly... I think he just had let it sink in a bit, but once he saw that I was completely ok with not contributing to the genetics, he was too."
I may find some success by expressing this exact same thing. Right now, he's thinking that his 44 year-old wife is going to beat the odds. I've been hanging around these boards long enough to know better, so I need to work gently and steadily toward an alternate route.
Thanks for sharing your story. Helps a bunch.