2 pair, scary flop vs. big stack - Completely lost

[Somekid]

I've been trying to figure out SNG play. I'm horrible. I really have no idea what happened here. What did I do wrong?

Party Poker No-Limit Hold'em Tourney, Big Blind is t30 (7 handed) converter

Button (t695)
SB (t1375)
Hero (t880)
UTG (t1305)
MP1 (t440)
MP2 (t455)
CO (t2850)

Preflop: Hero is BB with J[img]/images/graemlins/club.gif[/img], T[img]/images/graemlins/diamond.gif[/img].
<font color="#666666">3 folds</font>, CO calls t30, <font color="#666666">2 folds</font>, Hero checks.

Flop: (t75) 9[img]/images/graemlins/club.gif[/img], T[img]/images/graemlins/heart.gif[/img], J[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(2 players)</font>
Hero checks, <font color="#CC3333">CO bets t30</font>, <font color="#CC3333">Hero raises to t150</font>, CO calls t120.

Turn: (t375) 3[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">Hero bets t275</font>, CO calls t275.

River: (t925) A[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(2 players)</font>

Final Pot: t925