The Midnight Library by Matt Haig

Nora's life has been going from bad to worse. Then at the stroke of midnight on her last day on earth she finds herself transported to a library. There she is given the chance to undo her regrets and try out each of the other lives she might have lived. Which raises the ultimate question: with infinite choices, what is the best way to live? THE NUMBER ONE SUNDAY TIMES BESTSELLER. AN INSTANT NEW YORK TIMES BESTSELLER. WINNER OF THE GOODREADS CHOICE AWARD FOR FICTION. A BETWEEN THE COVERS AND GOOD MORNING AMERICA BOOK CLUB PICK.