How bad did I screw this up?

[Wolf101]

Villain bluffed twice early in the tourney ($5.50) and got caught both times, it almost put him out both times. PF raising was non existant the whole tourney. Still, I didn't enough...should I have pushed on the flop?

PokerStars Hold'em No Limit - Level VI (100/200)
Seat #9 is the button
Seat 3: Villain (6185 in chips)
Seat 8: Hero (1980 in chips)
Seat 9: Bystander (5335 in chips)
Villain: posts small blind 100
Hero: posts big blind 200
*** HOLE CARDS ***
Dealt to Hero[Qh Qs]
Bystander: folds
Villian: raises 200 to 400
Hero: raises 200 to 600
Villain: calls 200
*** FLOP *** [5h 5s 7d]
Villain: checks
Hero: bets 400
Villain: calls 400
*** TURN *** [5h 5s 7d] [8s]
Villain: checks
Hero: bets 400
Villain: calls 400
*** RIVER *** [5h 5s 7d 8s] [Kc]
Villain: checks
Hero: checks

Results in white below

<font color="white">*** SHOW DOWN ***
Villain: shows [3h Kd] (two pair, Kings and Fives)
Hero: mucks hand
Villain collected 2800 from pot

</font>