KQo in SB NL200 I messed it up so bad

[RiverIsMyFriend]

Poker Stars, $1/$2 NL Hold'em Cash Game, 6 Players
LeggoPoker.com - Hand History Converter

BTN: $385.40
Hero (SB): $225
BB: $176.55
UTG: $192
MP: $206
CO: $130.40

Pre-Flop: Q[img]/images/graemlins/club.gif[/img] K[img]/images/graemlins/heart.gif[/img] dealt to Hero (SB)
<font color="red">UTG raises to $7</font>, MP folds, CO calls $7, BTN folds, Hero calls $6, BB calls $5

Preflop call is kind of loose. But I don't think it's a major mistake.

Flop: ($28) 3[img]/images/graemlins/spade.gif[/img] 2[img]/images/graemlins/diamond.gif[/img] K[img]/images/graemlins/club.gif[/img] (4 Players)
Hero checks, BB checks, <font color="red">UTG bets $16</font>, CO calls $16, Hero calls $16, BB calls $16

I'm quite confused by CO's call here. But I think lots of time I'm ahead. I didn't raise because I figure most hands I beat probably won't call the raise. The board is dry so there are very few dangerous cards that can really hurt me.

Turn: ($92) Q[img]/images/graemlins/diamond.gif[/img] (4 Players)
Hero checks, BB checks, <font color="red">UTG bets $32</font>, CO folds, Hero calls $32, BB calls $32

Now I'm very sure that I'm ahead. I was kind of worried about AK because UTG is kind of tight. I should definitely raise here, right?

River: ($188) 6[img]/images/graemlins/diamond.gif[/img] (3 Players)
Hero checks, <font color="red">BB bets $50</font>, UTG folds, Hero calls $50

BB waked up which pissed me off.