If Tomorrow Doesn't Come - Jen St. Jude
Sometimes, love is an apocalypse...
On the morning Avery Byrne plans to end her life, the world discovers there are only nine days left to live: an asteroid is headed for Earth, and no one can stop it.
As time runs out and secrets slowly come to light, Avery fights her way home to save the girl she has been in love with her whole life. But can Avery also learn to save herself and find hope again in the tomorrows she has left?