($11) Awful play w/55; how to improve?

[Pokey]

<font color="blue">I'm starting to feel antsy with the antes getting to t50 and t100; I'm making the occasional steal, but not really playing hyper-aggro yet. Here, a routine blind-steal goes horribly awry. How can I play this one better?</font>

Party Poker No-Limit Hold'em Tourney, Big Blind is t100 (7 handed) FTR converter on zerodivide.cx

BB (t1060)
UTG (t1350)
MP1 (t1715)
Pokey (t885)
CO (t1885)
Button <font color="orange">(Villain)</font> (t615)
SB (t490)

Preflop: Pokey is MP2 with 5[img]/images/graemlins/heart.gif[/img], 5[img]/images/graemlins/diamond.gif[/img].
2 folds, <font color="red">Pokey raises to t300</font>, 1 fold, Button <font color="orange">(Villain)</font> calls t300, 2 folds.

Flop: (t750) A[img]/images/graemlins/diamond.gif[/img], K[img]/images/graemlins/heart.gif[/img], Q[img]/images/graemlins/club.gif[/img] <font color="red">(2 players)</font>
<font color="red">Pokey bets t100</font>, Villain calls t100.

<font color="blue">Betting the question "are you as scared by that flop as I am?" Answer: no.</font>

Turn: (t950) A[img]/images/graemlins/heart.gif[/img] <font color="red">(2 players)</font>
Pokey checks, <font color="red">Villain bets all-in [t215] </font>, Pokey folds.

<font color="blue">The final all-in bet was about half my stack at that point, and I figured that Villain probably had an A, K, Q, or better pocket pair to have bet the way we'd seen. I cut my losses and ran.</font>

Final Pot: t950

<font color="blue">Berate me if necessary, mock me at will, but please let me know what I could have done better in this hand, even if the answer is "don't play this hand."</font>