One thing to think about - changes in early recovery can be quite significant and your husband may not be able to relate or really grasp how much a support group like 'SR' can really help.
It's funny how when we're feeling insecure our imaginations can jump to assuming the worse.
On top of the great comments above, you might want to try getting him both to a safe place with similar support for himself - IE alanone, so that what you're doing isn't such an unknown (and frightening) mystery and he can see that, yes, a support group would add value.
He may also be feeling a little helpless as your taking your 'own' journey and that can trigger insecurities. Change is scary.
One thing to try - when he does something that is helpful for you sobriety, recognize it, both as a way to encourage more of the types of things that you need & to involve him so that he doesn't question is role in this
