A shadow, a dark reflection i am unable to see

Title: a shadow, a dark reflection I am unable to see.
Genre: horror/ thriller
Theme: suicide, split personality.
Plot: Suicide of a troubled young teen who is diagnosed with split personality and has a belief that she is a reincarnation of a women, an women astronaut who died years ago, she thinks that she’s that women when her other personality takes over. She doesn’t understand what happens to her and she came to this conclusion. She starts to have hallucinations of her “past” and goes on to try and find out. Her other personality finally takes over her and forces her to obey the other her. Her second personality finally tells her to write her own farewell.
Characters: sunita Williams
Voice: 1st person
Setting: 1940, world war one beginning. Set in Britain