I think he might simply be asking for you to say thank you for all the time and love he contributed as you moved through the crisis of your drinking and early recovery.
Although we talk so often about having to do this for ourselves, and - to be honest - want most of the credit for our recovery (ok, we'll give AA or God a shout out), we are reluctant to credit our partner.
I think this has to do with a need for self-empowerment and the positive self-image that we were brave and took on something really challenging. But, it is a very individualistic perspective. We are part of the organism of our community and family, and every change we've made in ourselves has impacted them and been impacted by them, whether we acknowledge that or not.
It sounds as though you really love your partner, and value him as your friend. Give him a gift and tell him how much you needed him then and how much you still need him. You becoming sober doesn't have to mean that he loses his role and sense of meaning as your supportive being. There is a difference between interdependence and co-dependence. The latter is the unhealthy expression of what is an essentially healthy and wonderful human behavior. Caring for each other and taking care of each other is what makes the heart glow and grow. I suspect that he is feeling somewhat replaced by your super-involvement in the program; you may just need to "manage" those emotions with a little bit of caring sensitivity and intentional re-connection...