John Cena Says 'Heart Hurts' After Split with Nikki Bella

John Cena says he's emotionally devastated after his breakup with fiancee Nikki Bella ... saying, "I love Nicole with all my heart and the split's tough."

The WWE superstar says he was expecting reporters to ask him questions about the splitwhile promoting "Bumblebee" at CinemaCon in Vegas ... and decided he's ready to talk about it.