I call it a book hangover. The best thing is to start a new engaging story.

“Child, child, have patience and belief, for life is many days, and each present hour will pass away. Son, son, you have been mad and drunken, furious and wild, filled with hatred and despair, and all the dark confusions of the soul - but so have we. You found the earth too great for your one life, you found your brain and sinew smaller than the hunger and desire that fed on them - but it has been this way with all men. You have stumbled on in darkness, you have been pulled in opposite directions, you have faltered, you have missed the way, but, child, this is the chronicle of the earth. And now, because you have known madness and despair, and because you will grow desperate again before you come to evening, we who have stormed the ramparts of the furious earth and been hurled back, we who have been maddened by the unknowable and bitter mystery of love, we who have hungered after fame and savored all of life, the tumult, pain, and frenzy, and now sit quietly by our windows watching all that henceforth never more shall touch us - we call upon you to take heart, for we can swear to you that these things pass.”

― Thomas Wolfe, You Can't Go Home Again