is there something inherently wrong with me

16f. I've never really been much of an introvert (though I try to avoid going out when I can). I make friends pretty easily and I can talk to most people, yet I'm struggling in my relationships. Many of my friends in school have been actively leaving me out of activities and conversations. I feel like an accessory to most groups and my presence feels expendable. I don't get into drama, I don't talk shit about anyone I'm friends with, and I overcompensate by taking on their habits of speaking, humor, and interests so they can like me a bit more. As I went into high school, I molded myself to become more appealing to people and I made a lot of friends, yet all that effort feels ultimately futile. I don't belong anywhere I go, not since the day I was born. I'm the black sheep of my family (yes, even as an only child), the stain in my friend groups, and the one floater everybody goes to when their "actual" friends can be with them. I only have one really good friend, but she lives in a different state. Even then, she always talks about how close she is with her boyfriend and other best friends and I can't help but feel worse and even lonelier.

Even simple interactions with people are tiresome and trite. Every conversation I have with people feels like small talk. I don't enjoy anything. I try so hard, but I can't feel fulfilled by any conversation I have with them. It feels like time dilates, and I can feel my mind materialize and piece together huge rifts between me and everybody else. I'm missing something that makes them click--something that I don't have.

A lot of this has manifested into deep insecurities about my own faculties. I feel much less accomplished, talented, pretty, intelligent, witty, and charismatic than everybody else around me. I feel like a shell of a human being with no outstanding traits. I have my own interests, my own identity, and a good idea as my standing as a human being--yet I can't help but feel inadequate/emptier to everybody else. Talents I thought I had, and a vision for a future that I manifested for so long, seem to be slipping through my fingers like an inviscid liquid. I feel like nothing, I feel like I am a nobody. I can't achieve anything.

I don't like feeling this way. I don't know what to do. My therapist, my parents, and my best friend don't understand me and they don't give me any solutions or steps. Is there something wrong with me? Am I just a naturally a socially inept person? My mom and dad say I'm incredibly sarcastic wording on rude, but that's how a lot of my "friends" at school talk to me too. Or it is just my lack of admirable traits? I've noticed that all the more academically high achieving people and conventionally attractive people tend to accumulate friends very easily. My therapist, my friend, and my parents have all said that it's not my fault but if its happening within every social group I'm in, there has to be a common denominator, right? A key factor?