Why do I have this?

With the research I’ve done on this all I see is that it’s common among people who experience loneliness, anxiety and depression. But I haven’t gone through most of these things throughout my life minus some moments of depression and anxiety that are short lived.

I don’t have social anxiety because I feel like socially I get along with people and have been surrounded by people most of my life. So the question is why have I been doing this my whole life?