I suck (folded a set of jacks on the flop)

[Xanta]

NOTICE STACK SIZES BEFORE YOU FLAME PLZ

Party Poker - No Limit Hold'em Cash Game - $1/$2 Blinds - 6 Players - (LegoPoker Hand History Converter)

SB: $435.20
BB: $216.90
UTG: $403.10
MP: $208.85
Hero (CO): $391.00
BTN: $37.00

Reads: <font color="blue">Hero built his stack in like 8 hands by playing really aggro preflop then bet/shoving aces into jacks preflop. Villain is more or less unknown, but has the name UTG making me think he's less donkish. Don't know how he got his stack</font>

Preflop: Hero is dealt J[img]/images/graemlins/heart.gif[/img] J[img]/images/graemlins/spade.gif[/img] (6 Players)
<font color="red">UTG raises to $7.00</font>, MP folds, Hero calls $7.00, 3 folds

Flop: ($17) K[img]/images/graemlins/diamond.gif[/img] J[img]/images/graemlins/club.gif[/img] Q[img]/images/graemlins/club.gif[/img] (2 Players)
<font color="red">UTG bets $12.00</font>, <font color="red">Hero raises to $50.00</font>, <font color="red">UTG raises to $140.00</font>, Hero folds

Pot Size: $207.00

I'm pretty awful at playing deep, but I'm sure that preflop and flop are good. How do react to his 3bet?