Sounds to me like you haven't had much practice making friends. I thought I was like that myself, until I got into sales work. I discovered that, owing to having moved fairly frequently as a child, and very frequently as a military man, I was actually very efficient at making friends. I had just been satisfied with making a small circle of friends and acquaintances. If I were just to keep at being friendly, and being interesting by being interested, I could have lots and lots of friends and aquaintances by just talking to people.
The really enduring friendships come from doing the really fulfilling things (whichever things those are) in the company of others who find fulfillment in the same things. That's a big reason the
Society for Creative Anachronism still holds its membership.