disgusting spot w middle set

[luegofuego]

totally sick.... was completely confused here. what should i have done?

button is g000ber, CO is a lagfish.

Party Poker No-Limit Hold'em, $ Hero (6 handed) Hand History Converter Tool from FlopTurnRiver.com (Format: 2+2 Forums)

CO ($6407.30)
Button ($2640)
SB ($1960)
Hero ($6490.84)
UTG ($4300.68)
MP ($1990)

Preflop: Hero is BB with 5[img]/images/graemlins/spade.gif[/img], 5[img]/images/graemlins/heart.gif[/img]. SB posts a blind of $10.
<font color="#CC3333">UTG raises to $70</font>, <font color="#666666">1 fold</font>, CO calls $70, Button calls $70, SB (poster) calls $60, Hero calls $50.

Flop: ($350) 5[img]/images/graemlins/club.gif[/img], 4[img]/images/graemlins/diamond.gif[/img], 9[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(5 players)</font>
SB checks, <font color="#CC3333">Hero bets $260.3</font>, UTG folds, <font color="#CC3333">CO raises to $620</font>, <font color="#CC3333">Button raises to $1555</font>, SB folds, Hero folds, CO folds.

Final Pot: $2785.30