This is not okay. It’s not how you’re meant to feel. And it seems you are aware of that.
It means firstly you probably watch too much porn. On top of which you are likely suffering with some serious anger, pain and emotional hurt that will somehow have their root in your past.
You’re smart enough to know this is a bad. Now be smart enough to get some help with loving yourself and not wanting such self-destructive things.
Find some people who love you for who you are. Maybe look into some professional support to deal with the pain, frustration and anger you probably feel. At the very least, find someone to talk to about this, because a big part of dealing with these feelings is just acknowledging them and realising they don’t define you (maybe avoid sharing the rape and kill fantasies at first, just stick to describing how you feel in general).
I suggest you take a break from porn, it’s not doing you any good right now. If you can’t at least cut out any extreme porn. It only takes a week or so to get it out of your system.
You are not defined by this, it’s just the headspace you’re in right now. It will pass, and one day you’ll look back and say ‘what the fuck was I thinking’ and maybe even laugh. Take some baby steps to moving on from feeling this way and that day won’t be too far off at all.
Good luck.