As a person both interested in guro and self-hating, I'd have to say that a lot of my self-hate isn't expressed in my attraction to death. However, I have gone though periods of time when I would have very dark and disturbing daydreams, much like a person would have a nightmare. Dreams of me being brutalized or physically/emotionally destroyed by strangers or even close friends.

I've never understood why I do it, aside from a strange feeling of catharsis that I get with it.

It's almost certainly not 'healthy' to imagine yourself being brutalized. If you can't get the help you need from your family, seeking help outside of your family isn't a bad or wrong thing. You should especially seek help if you ever start seriously considering enacting your fantasies on yourself in reality.

Please try and understand that there are people who care about you, even if they don't really know you and even if you don't know them. There are people that will want to help you.