I've had a few long-term friendships. They ended when the other person "outgrew" me. I currently have a few long-term relationships that haven't ended yet. I have a fiance (we're not married, but it seems wrong to call him a "boyfriend" because he's an adult and "man-friend" just sounds plain dumb) but he's a very strange person. He's an NT, but he prefers autistic people to other NTs. I have two other close friends. One is the mom of my son's best friend. And the other is a neighbor who comes over for lunch every weekend who I've known for 20 years. Good people. None of them were easy to find and I consider myself lucky.
The trouble I've found with making friends is that my definition of "friend" is very different from the definition held by most adult NTs. I define "friend" as a person I can trust unconditionally that I enjoy being around, who feels the same about me. Adult NTs define "friend" as a person they can use towards a goal, who won't immediately back-stab them. That kind of friend is what I would call an ally. In my way of thinking, that's not a real friend.
So why don't you have any long-term or lifelong friends? Did they move away? Or did they decide they needed allies more than friends, like a lot of my previous friends did? Would you like to try to be friends with me? I don't think anyone who wants a friend should be without. In varying degrees, most people have a need for friendship.