Out foxed by a better player or am I just dumb?

[biggambler]

3-6 holdem at Turning Stone. I'm in the big blind. EP is a 10-20 player who walked over because the big game broke up.Four calls to me, I look down and see 6 Clubs,9 Hearts. I rap.
Flop comes 7,8, K. Two diamonds. EP bets all call including me. Turn is the 5 of Spades. All chek to me, I bet. Everyone calls. River comes the J of Diamonds. All check to me. I bet, EP ck raises me. I make crying call. Out