Am I ever scared of this bet on the river? (BIG bet)

[n4rf]

Full Tilt No-Limit Hold'em, $0.10 BB (5 handed) Full Tilt Converter Tool from FlopTurnRiver.com (Format: 2+2 Forums)

Button ($14.30)
SB ($9.90)
Hero ($14.55)
UTG ($7.95)
MP ($12.20)

Preflop: Hero is BB with K[img]/images/graemlins/heart.gif[/img], K[img]/images/graemlins/club.gif[/img].
<font color="#666666">2 folds</font>, <font color="#CC3333">Button raises to $0.3</font>, SB calls $0.25, <font color="#CC3333">Hero raises to $1.5</font>, Button folds, SB calls $1.10.

Flop: ($3.20) 2[img]/images/graemlins/heart.gif[/img], 5[img]/images/graemlins/spade.gif[/img], T[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(2 players)</font>
SB checks, <font color="#CC3333">Hero bets $2.2</font>, SB calls $2.20.

Turn: ($7.60) 7[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(2 players)</font>
SB checks, Hero checks.

River: ($7.60) 4[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">SB bets $6.3 (All-In)</font>


Villain is Unknown

Should I have bet the turn as well and folded to resistance?

As played, what would you do here?