The Taste of Blue Light by Lydia Ruffles

What happened to me?
Why can't I remember?
Weeks after blacking out and waking up in hospital, Lux still has no memory of what happened.
She doesn't know why her days are consumed by pain and her nights by terrifying dreams; why her parents won't stop shouting and her friends stop talking when she walks into the room.
All she knows is that the Lux she once was is gone - and that if she can't uncover the truth, everything she loves will be taken away too.