QQ gets 4bet

[eBo]

This is a common situation that has been killing me lately.

PokerStars No-Limit Hold'em, $6 BB (6 handed) Poker Stars Converter Tool from FlopTurnRiver.com (Format: 2+2 Forums)

MP ($1494.20)
CO ($600)
Hero ($1143)
SB ($618)
BB ($1686.20)
UTG ($579)

Preflop: Hero is Button with Q[img]/images/graemlins/spade.gif[/img], Q[img]/images/graemlins/heart.gif[/img].
<font color="#666666">2 folds</font>, <font color="#CC3333">CO raises to $24</font>, <font color="#CC3333">Hero raises to $72</font>, <font color="#666666">2 folds</font>, <font color="#CC3333">CO raises to $204</font>

Hero?

I'm a 3betting addict, but villain is probably a donk because of his prior weird bet sizes.

If I fold then this is very exploitable. However, there are too many nits at this stage who only 4 bet w/KK+. What to do?