KK : did I chose the right line??

Party Poker No-Limit Hold'em, $ BB (6 max, 6 handed) FTR converter on zerodivide.cx

The villain has an unusual style of play, often staying in to reasonable bets with very little, and seeing the hand thru. This is making him/her a steady winner.

CO ($36.35)
Hero ($28.38)
SB ($24.75)
BB ($12.15)
UTG ($13.65)
MP ($20.95)

Preflop: Hero is Button with K[img]/images/graemlins/club.gif[/img], K[img]/images/graemlins/diamond.gif[/img]. SB posts a blind of $0.10.
UTG calls $0.25, MP calls $0.25, CO calls $0.25, <font color="#CC3333">Hero raises to $2</font>, <font color="#666666">2 folds</font>, UTG folds, MP folds, CO calls $1.75.

Flop: ($4.85) 4[img]/images/graemlins/spade.gif[/img], 9[img]/images/graemlins/heart.gif[/img], 9[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(2 players)</font>
CO checks, <font color="#CC3333">Hero bets $3</font>, CO calls $3.

Turn: ($10.85) J[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(2 players)</font>
CO checks, <font color="#CC3333">Hero bets $6</font>, <font color="#CC3333">CO raises to $12</font>, Hero calls $6.

River: ($34.85) 7[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">CO bets $5</font>, Hero raises $6.38 (all in) CO calls $6.38.

Final Pot: $46.23

So, did I mess up? or just unlucky??