KK against a big stack

[Johnny McEldoo]

I've been playing LHE for a long time and moving from limit to NL is difficult for me in these types of spots.

Villian is a 40/19/1.88 who has not been out of line. Have about 200 hands on this guy all from this table. I have been raising a good amount of pots lately but it has been from good run of starting hands. My showdowns have been strong. What the heck do I do here?

Poker Stars, $0.25/$0.50 NL Hold'em Cash Game, 5 Players
LeggoPoker Hand History Converter

Hero (BB): $185.05
UTG: $75.05
CO: $54.10
BTN: $23.75
SB: $151.55

Pre-Flop: K[img]/images/graemlins/club.gif[/img] K[img]/images/graemlins/spade.gif[/img] dealt to Hero (BB)
3 folds, SB calls $0.25, <font color="red">Hero raises to $2</font>, SB calls $1.50

Flop: ($4) 7[img]/images/graemlins/spade.gif[/img] 8[img]/images/graemlins/heart.gif[/img] 3[img]/images/graemlins/spade.gif[/img] (2 Players)
SB checks, <font color="red">Hero bets $2.50</font>, <font color="red">SB raises to $7.50</font>, <font color="red">Hero raises to $20</font>, <font color="red">SB raises to $149.55 and is All-In</font>

Hero?