How to play this nut flush draw

In my local 1-2NL cash game I ran upon this hand. First I'll preface everything by saying that people in this game can play any two cards limping in and sometimes w/ raises.

anyway, I was in LP and limped w/ K [img]/images/graemlins/diamond.gif[/img] 3 [img]/images/graemlins/diamond.gif[/img] after several limpers. I know, bad play but I digress. BB raises to 10straight, all but one calls including me. 6way pot. typical preflop. So $62 in pot(sb folded on raise).

Flop comes A [img]/images/graemlins/diamond.gif[/img] Q [img]/images/graemlins/heart.gif[/img] 8 [img]/images/graemlins/diamond.gif[/img] Super tight player checks, but obviously hit. Loose player makes it $15 and 2 callers, then I call and then tight player raises $50. I put him on AQ as he would of raised $100 w/ QQ or AA. Original bettor folds to me, one person left to act behind me who is obviously folding. $173 in pot including $50 raise.

I have $183 left in front of me and raiser has 3-4hundred. What's the proper play.