Why doesn't anyone understand my hatred?

I am 16, Caucasian male. I don't understand why my family does not take me seriously/understand me when I say that I hate my sister. This is not just whiny b*tch teenager stuff, the sight, sound or even the memory of her makes me want to vomit. If it was a choice between her life or a minor injury to me I would avoid the injury. She is a vile, vicious, condescending snake-. I despise every facet of her; appearance, opinions, actions, voice and I feel that on a fundamental level our souls were not meant to interact. Can anyone please tell me how to convince my parents of this?