Living Backwards by Tracy Sweeney

Twenty-nine-year-old Jillian Cross refuses to believe that a pair of skinny jeans has led to her untimely demise. Life just isn't that cruel. But when an overly-enthusiastic attempt at squeezing herself into them leads her to fall and lose consciousness, she is faced with just that possibility. When she awakens with both a bruised ego and a bump on her head, she's not in her tiny apartment but her childhood bedroom circa 1999-the spring of her senior year in high school. Jillian knows that time travel isn't logical. But then again, neither was her decision to wear skinny jeans. As she attempts to navigate her way through the halls of Reynolds High, walking the same path and making the same choices she made years before, she knows that any change she makes can have a catastrophic effect on her future. But when she strikes up an unexpected friendship with motorcycle-riding, cigarette-smoking Luke Chambers, can she pretend to be the same shy girl she once was? At least she has her pink sparkly flask to take the edge off. One little change won't hurt, right?