10/20NL 6max, I think I screwed this Part II

[fuzzylogic]

I really hate myself when I freeze in big pots (like 200BB behind or so) when I have less than the nuts. Villain is solid winner in my stats ~20/16

Party Poker No-Limit Hold'em, $ Hero (6 handed) internettexasholdem.com

saw flop|<font color="#C00000">saw showdown</font>

SB ($380)
Hero ($4207.76)
UTG ($5513.14)
MP ($779.50)
CO ($2000)
Button ($1838)

Preflop: Hero is BB with K[img]/images/graemlins/spade.gif[/img], K[img]/images/graemlins/heart.gif[/img]. SB posts a blind of $10.
<font color="#CC3333">UTG raises to $80</font>, <font color="#666666">1 fold</font>, CO calls $80, <font color="#666666">2 folds</font>, <font color="#CC3333">Hero raises to $330</font>, UTG calls $270, CO folds.

Flop: ($790) J[img]/images/graemlins/heart.gif[/img], 4[img]/images/graemlins/spade.gif[/img], 4[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">Hero bets $500</font>, UTG calls $500.

Turn: ($1790) 6[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(2 players)</font>
Hero checks, <font color="#CC3333">UTG bets $900</font>, Hero ??

I should lead here and evaluate then if I get raised, right?
If you bet here and get raised is that a fold then? If he just calls and river blanks do you just shove or ?