I sometimes feel that I am not an ordinary person.

It's simple. You think too much and do too little, so it feels unreal. You need to get in touch with more people and do things with everyone. When doing things, don't think about anything else, concentrate on doing your own thing and feel the ups and downs of life more. Only in this way can there be a sense of existence. Death is inevitable, but it's not what you should worry about now. You'll understand when you get old, just like when you were a child. When you grow up, you will naturally be afraid of death, but when you grow up, you will want to go back to your childhood. Maybe you'll be dull when you're dying. As long as you have worked hard and struggled, the result is not important.