Opposite of Always - By Justin A. Reynolds

When Jack and Kate meet at a party, bonding until sunrise over their mutual love of Froot Loops and their favorite flicks, Jack knows he’s falling—hard. Soon she’s meeting his best friends, Jillian and Franny, and Kate wins them over as easily as she did Jack.
But then Kate dies. And their story should end there.
Yet Kate’s death sends Jack back to the beginning, the moment they first meet, and Kate’s there again. Healthy, happy, and charming as ever. Jack isn’t sure if he’s losing his mind.
Still, if he has a chance to prevent Kate’s death, he’ll take it. Even if that means believing in time travel. However, Jack will learn that his actions are not without consequences. And when one choice turns deadly for someone else close to him, he has to figure out what he’s willing to do to save the people he loves