Memory loss?

Backstory

Your probably so confused here is the truth...

There was a girl called Angelina she's my sister well she was at least I was so jealous of her she's so pretty and everyone loves her but me no I'm not. No one even looks at me all the eyes are on her, she had the perfect job perfect apartment I was just viewing the story in her eyes that's what most of this story is about I'm Kate the girl who killed her sister to find out she was never dead.

That's the reason I'm dead. 6ft underground buried but I'm not dead I'm just buried alive and everyone thinks I'm dead. No one even cares there's no flowers on my grave no one even visits not even Angelina how did she come back to life? But im going to make sure that's not the last she sees of me...