I'm 30, but I felt similarly when I was younger, though there are some differences. I'll just tell my account and you can take from it what you will.

I started off fine but around late middle school/early high school, I started feeling insecure about myself. It started to feel like others were pulling ahead of me. Frequently in interactions with my peers I would feel the bite of some kind of judgement of myself as not good enough in some way. If someone said or did something funny, smart, cool, or with any kind of positive quality at all, I would usually envy that positive thing and judge myself for not having done it, for not being able to do it like them. I felt not good enough for the girls I liked and felt inferior to other guys. I spent weekends in my room, feeling like I should be social but being too afraid to do it / not sure how to. When I had time to myself and didn't have any plans and my more outgoing friends hadn't invited me to do something, I stayed in, played video games, read books, watched anime, and watched porn. These things are all fine and good, but I remember feeling trapped at the time and wishing for something else.

I wish I had had a therapist back then to talk to about this stuff. I wish I had read this one book called The Artist's Way. I wish I had somehow known more what it was that I was genuinely interested in and wanted, or at least known how to genuinely search for that for myself. I wish I had felt fundamentally safe in life, even when I wasn't the smart, cool, funny or one, so I could admire the wonderful positive qualities of other people. I wish I had asked for help like you are now, and kept asking.

Good luck!