A contributing factor to this may be the fact that I've be physically abused in school. I'm homeschooled because of bullying and I have a hard time socializing. I also suffered from verbal abuse and my self-esteem is extremely low because of it. I'm so sensitive that just about anything hurts my feelings. I stress myself out so much I believe it caused me to have a terrible headache today. I really need help. I don't want to act on these thoughts.
I haven't told my mom because I'm afraid she will be angry with me for having such terrible thoughts about my own sister.

I tried reasoning with my sister, but like I said, she's spiteful. She won't stop because she loves to do it. My mom also does nothing about the fighting. She is afraid to say anything to her.
I'm also bitter because most of my family members favor others over me. I was betrayed by everyone I called "friend." Even my cousins won't be there for me. They're friends with the people who bullied me!