Not wanting to make new friends

So those who have been keeping up with my story, my wife and I have reconciled and are doing pretty well. One of our agreements was to expand our individual friendship base so we're not so dependent upon each other. While my wife isn't having too many issues finding new friends, I find myself struggling to even want to. I've never really been the social butterfly. I have my small core group of friends, but we're not really go hang out friends if that makes sense. My wife has always been my best friend and the only friend I felt I needed. Is it healthy to feel that way? Is it wrong to not want to make other friends? How do I even open myself up to finding new friends? I'm just not sure what to do.