It was a string of unfortunate circumstances and events, I think.
First off, I'm pretty sure I was born an introvert. I never felt much need for socializing or friendship; I remember when I was really young, I only ever wanted to play with one "best friend" -- I didn't like the idea of having a group of friends. Then there was the perfectionist religious environment I was brought up in; my parents were really serious about it when I was a kid, and the pressure to conform was enormous. I always felt like I could never be good enough, like 'god' hated me personally. I struggled with 'faith' throughout my late childhood, teens and early 20's. When I was 8 we moved from California to Utah and I absolutely hated it; I never made any new friends, and quickly became bitter and jaded. I think that attitude led at least in part to the bullying, which started when I was about 10 and didn't stop until we moved overseas when I was 13. That was the primary trigger; I very nearly killed myself in the 8th grade.
Of course the years of torment completely destroyed my confidence, self-esteem and capability to trust. After that I shut myself off from other people completely; I never made any friends again. I moved around from clique to clique in high school, never really joining in with anyone; I never talked to anyone unless I had to. I think I was improving, until University made it worse -- I was again immersed in the religious culture that I hated, which dredged back up all the depression and anxiety. After I graduated I officially resigned from my parents' religion, which helped. But by then the damage was already done. And I've been "surviving" ever since.
I've tried therapy a few times but it never did much. I also tried a string of different medications in my late 20's but hated the side-effects. Recently I've been feeling the depression welling back up, and at this point I don't even care anymore. Let it come; I've weathered it before, and I will again. **** it all.
this is so sad bro , so you was basically born with it ,your bullies will meet their fate pretty soon , me myself im at a moment where i dont care anymore what happens to me or i dont care about family members, i had too many friends at that time before the accident now im only with a few people who are close friends , this is a persona that developed from my depersonalization and depression and i cant change it no matter what i do ,my new lifestyle or the way i see the world ends with one word illusion , i told myself that everything that i see now its all fake and an illusion this is how i became more aware of my depersonalization because being in that state is also a feeling where it feels like an illusion , nobody in my family could understand what i had going on mentally , nobody except my doctor