Struggling to control his emotions, Lionel Messi said Sunday in his farewell to Barcelona that he wasn’t prepared to leave the club.Messi began crying even before he started speaking at his farewell ceremony at the Camp Nou Stadium.”This is very hard for me after so many years, after being here my entire life,” he said. “I wasn’t prepared.”Messi called his unexpected departure from the club “the most difficult” moment of his career.Messi’s family and some of his teammates were at the Camp Nou for the player’s farewell.Messi avoided speaking specifically …