How should I have played this?

[cartman]

Villain is unknown. There is a big fish at the table who is currently sitting out, so this hand is played heads up with the villain as the big blind on the button.

PREFLOP: Hero open-raises in the sb with J[img]/images/graemlins/club.gif[/img]9[img]/images/graemlins/diamond.gif[/img] and villain has the raise any button clicked and instantaneously 3-bets.

FLOP: J[img]/images/graemlins/heart.gif[/img], 8[img]/images/graemlins/spade.gif[/img], 6[img]/images/graemlins/heart.gif[/img]
Hero checks, Villain bets, Hero calls (planning on check-calling the turn and maybe donking the river).

TURN A[img]/images/graemlins/heart.gif[/img]
Hero checks, Villain bets, Hero <font color="blue">?</font>


What do you think of my flop line and my plan?

What should I do now?

Would your answer change if the 8 on the flop were a 7 instead (removing my gutshot)?


Thanks,
Cartman