What are you supposed to do if you have no friends as an adult?

As the title says, I have no friends, and it’s really beginning to take a toll on me. I don’t have a single close friend in my life that I can consistently rely on. The vast majority of people that even slightly resemble “friends” in my life ignore me regularly, never want to be seen in public with me, and have always given me empty, fake gestures of pity for clout. They treat me like some inferior zoo animal. They’ll leave me on read and then go out posting pictures of themselves with their “real” friends at parties and other fun gatherings.

My entire adolescence and adulthood thusfar has been watching, either through media or in person, other people experience intimacy in terms of friendships and romance while being totally incapable of knowing what it’s like. While being shut down, rejected, turned away, and passed over in every way imaginable.

What is wrong with me? What am I doing wrong? I’m 24 years old and am missing out on the prime of my life. People say I’m a funny person. People say they like me, but their actions ALWAYS conflict with that. I’ve never been anyone’s first choice ever. I’ve never been popular.