cynical_civilian
Possessive was the right word to describe her. She hated lending people things, and although others see it as selfishness, she sees it as a defense mechanism.
Obsessive was another word that described her perfectly; she became easily infatuated with certain crushes in the past, going as far as to follow them home.
But she wasn't always like this. At least, she believes so. To a person who knew her true colors, she was mentally unhealthy. But to herself, she seemed so normal.
After all, what's wrong with killing the woman who's been being too touchy-feely with whom you assume is yours?
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Read the story to see how someone's sanity is crushed to pieces within seconds, with the protagonist slowly becoming the shell of who she was before- only to become a sick person who society sees as evil and a filthy wrong-doer.