op is 18/15 over large sample agg on the flop but not so much on turn and river

i dont know what to do

PokerStars No-Limit Hold'em, $4 BB (6 handed) Hand History Converter Tool from FlopTurnRiver.com (Format: FlopTurnRiver)

MP ($274.95)
CO ($425.80)
Button ($400)
Hero ($590.30)
BB ($406)
UTG ($537.90)

Preflop: Hero is SB with T, T.
2 folds, CO raises to $14, 1 fold, Hero raises to $44, 1 fold, CO calls $30.

Flop: ($92) K, K, 8 (2 players)
Hero bets $60, CO calls $60.

Turn: ($212) 4 (2 players)
Hero checks, CO checks.

River: ($212) J (2 players)
Hero checks, CO checks.

Final Pot: $212