The Unbecoming of Mara Dyer — Michelle Hodkin

Mara Dyer doesn't believe life can get any stranger than waking up in a hospital with no memory of how she got there. It can.
She believes there must be more to the accident she can't remember that killed her friends and left her strangely unharmed. There is.
She doesn't believe that after everything she's been through, she can fall in love. She's wrong.