/lit/ - Literature

My fantasies are stupid and I don't know if it's because I lack self-esteem.
In my day to day life, I'm incredibly confrontational but not in an overtly macho kind of way. I have a girlfriend and we've been steady for four years. I won't go through every detail, but the point is that I don't feel ashamed or bad about myself. Good sex life, very comfortable conditions, great relationship with both my parents, etc. I have literally made my hobby into my job.
My fantasies always revolve around being an outcast, and I don't mean just sexual ones. The nossies in WoD probably come closest to what I mean. I dream of being a deformed creature of the shadows. My favorite games are stealth games for this very reason, though I clearly roleplay a bit when playing them too.
In terms of sex, in real life I'm always playing a dominant role, but what I want most is to be cucked and humiliated. Again, this doesn't work with my real life scenario, so I self-insert as other people. I like to imagine I'm super skinny and weak, or have a tiny penis, or that there's some reason why nobody wants to even touch me. Basically, my main sexual fantasy is being a beta.
I just don't know why this is. I would unironically like some help to better understand what might be wrong with me.