It's a tough one, I imagine. My mother struggled with this post-retirement, though she's in her 70s. She has enough friends, but they're all aged out and disabled in one form or another. Her solution was to go back to work part-time, as she enjoys being among people. She also joined Meetup.com and has gone to some fun events and met some interesting people. Whatever is you do, I wish you luck and positive vibes, as they say.