When You Were Everything by Ashley Woodfolk 

It’s been twenty-seven days since Cleo and Layla’s friendship imploded. Nearly a month since Cleo realized they’ll never be besties again. Now, Cleo wants to erase every memory, good or bad, that tethers her to her ex–best friend. But pretending Layla doesn’t exist isn’t as easy as Cleo hoped, especially after she’s assigned to be Layla’s tutor. Despite budding new friendships with other classmates—and a raging crush on a gorgeous boy named Dom—Cleo’s turbulent past with Layla comes back to haunt them both.