Even though I am not mentally abused, I show all these signs. That is strange.
I propose diathesis-stress. While most might require negative life events like abuse, some of us (myself included) were born with thin skin. I ended up like Harry Potter should have with all the abuse and neglect he endured - but even without sleeping in a cupboard under the stairs and being beaten up by an older cousin, I still would have managed to become fucked up mentally. It's just my nature. Voldemort could have not existed, James and Lily could have survived, I could have been a fucking trust fund kid with magical powers, and it wouldn't matter. I'd find something to cry about, undoubtedly.
I don't mean to talk down to you, but have you also considered if perhaps you did face mental abuse? It's not always obvious or, as I like to say, "Lifetime soap-opera-worthy". For many years, I was unable to recognize my dad's behavior as the abuse it was.