For me, I find daily sitting meditation helps me a lot, along with a T'ai Chi Chih practice, to fill that "hole" inside. I have found people can't fill that hole, only we can. Lots of paths/practices to do that, from religion to spiritual practices, philosophical studies, journaling, etc.
I have let myself become isolated for a number of years, and now that I am older, it's hard to make new friends as old ones have died of or moved further away. I have my DH and my adult daughter, and my faithful dog.
But of course, that's not enough. I am not as mobile as I once was, with arthritis, so I am not as active. I haven't been a group joiner due to my hearing loss.
So, I do find balance by doing my meditation and I am getting more positive because of it. And I am reaching out and learning lip reading and ASL at this late date in my life. While I am HOH and wear 2 hearing aids, I know the day has come when "technology" is not always enough. So I am learning new ways to aid my communication with others, but I am also getting to know others through these classes who are like me and making new friends. And we are patient and supportive of each other because we understand what we are going through.
So, I say, pursue your interests. Reach out and keep learning. Don't stop growing. No matter how old we are!