I have no diagnosis. Felt I might be a bit towards the schizoid disorder at times.

I have this fantasy story. The person in the story that is an avatar for me is immortal, but suffers. His life events parallel mine, in an odd way. It is high fantasy. He is an amazing fighter, but hates fighting, has no friends, never had sex, one or two failed romance attempts, and is not appreciated by anyone. All people he meets eventually die. The gods are also plotting against him.
People in the story would view my avatar as a cold-blooded killer. But he was the most ethical person in the whole word. Extremely rigid ethics and extreme self-sacrifice, with no apparent reward to him. He is also way worse at selling himself to others than I am. And like I said, all people that finally would get to see him for who he actually is, respect him, love him, they would die.
The main idea was to put him through as much agony as possible.

Every night when I went to bed, I would think for hours about his story. I was in social isolation at time. He experienced things I wanted to experience, in a way.

At some point the storyline got so rich, I decided I had to turn it into a novel. But I struggled with that greatly. I wrote down many many pages. But when I read it back, it sucks. I would spend even more time arranging all the story events and trying to insert actual literature themes into the story. Trying to fix plot holes and make the plots seem logical, while having it twist in exactly the way I wanted.
I also felt that all other characters in the story were uninteresting and that the big problem with the main character was that he was too perfect and too obvious an avatar of the writer.

Later, I played with the idea of changing the story into one where an appealing bad guy is the main character, and my avatar only appears as a mysterious background character. I felt that keeping him mysterious might be much much better, rather than follow his story from childhood in extreme detail.