The Hurting by Lucy van Smit

Nell hates her sister's illness, her drunken dad, and the daily absence of her mum.

When she meets Lukas, adopted heir to a Norwegian oil fortune, she sees her escape: the two of them running away from the world. But Lukas has his own dark wishes, and soon it's clear that what joins them goes way beyond love.

This is survival ... and is any boy really worth her soul?