I understand the rage and the hate you must be feeling but, taking it out on helpless creatures or thinking about doing worse than that is only going to eat away at you heart and soul.
I know it's hard but, you've got to reach down inside of yourself and get hold of it or it will wreck your life.
You have to fight it and you most definitely need to see a doctor and therapist before it gets any worse.
Don't sit around and let it build. Find something to distract yourself from it. I understand the evil feelings too.
One can only take so much before one cracks. Try to find things that calm your nerves and focus on them.
If you want someone to talk to about, send me a pm.