I don't consider conditional friendships, friendships. They were never my friends, so I don't miss them.
And eyeslice, you know my situation and upbringing. I had nothing to fall back on socially. We bounced around from country to country so much when I was growing up that my so-called friends in the congregation were all I had. Yet at 18 I still managed to say enough! and move on. What helped me is that I went to college and met people whom I had intellectual interests, and developed some hobbies and met more people through that. I'm not the social butterfly type. I have few people I consider friends, but the people that I do consider friends are those people for whom I would give my life.
My mom tried to give me the whole, "where will you go, what do you have now speech", a clever way to try and make me feel powerless and alone, but realizing that the bros and sis' in the congregation were never my true friends made it easier for me. I turned to other interests. Perhaps you can do that too? Do you have hobbies? Do you like to collect stamps? Do you like vintage automobiles? Find something that gives you pleasure, is legal, and then find others that like those things. Then you form friendships based on common interests, and with time those people worthy of your friendship will come to the forefront and you'll have true friends.
Don't feel like you lost anything by quitting at age 50. You gained the rest of your life.