When you checked Flop, you showed weakness. You should have bet the Flop to get your villain to define his hand. My guess is villain is going to keep firing to try to get you to fold, no matter what he has. I would have bet the flop, and if he called and then checked the Turn I would have checked behind him, and then checked it down on the river, putting him on Ace/little. Or if he had reraised me on the flop, I probably would have bailed.