In his first concert since his brush with the law on Long Island Justin Timberlake told cheering fans: “It’s been a tough week.” But “you’re here and I’m here, and nothing can change this moment right now,” Timberlake said Friday night at the United Center in Chicago. “I know sometimes I’m hard to love but you keep on loving me and I love you right back,” he added, revving up the crowd even more. Timberlake was arrested and charged Tuesday in Sag Harbor with driving while intoxicated. Police said he was observed “operating his vehicle in an intoxicated condition,” shortly after midnight after …