I can relate a little: I didn't have normal teenage years either. I'm no old soul, but I mostly spent my time fantasizing, making up stuff and playing around with ideas mentally to the point where I've questioned if I'm a maladaptive daydreamer (I'm not). It's not as intellectual as it sounds, I promise. Actually, the "scenarios and characters" thing is quite like what I do, only I always imagine it more like a movie or TV show, rather than anything for my own interaction. I still do it, even as I'm out in the world more.

I've pushed people away my entire life, even though the loneliness hurts sometimes. I'm of a mixed opinion on people: so I want them in my life or not? Perhaps you feel the same?

I can't offer much more than that. I don't know how or if it changes, I'm just a few years older than you.