Flush draw vs. 2 pair

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Heres the deal. blinds are 1 and 2. 7 people in the game, 3 limp in including me. both have postion over me. I limp in with 2 very low connectors.
I flop 2 pair. There is a queen out(not one of my pairs) and two of the cards is suited up(diamond). I bet 20 and one caller, so it is heads up. The villian has 120 and I have alot more(320) in our stacks.
Next card is a low card and it's a club, so no flush. He checks, I bet 20, and he stays in.
The river is a diamond, and I am not sure whether he just a Q(top pair) or a flush.
He bets 50, and like a retard, I call. He has an AdQd flush and I lost. Extremely dumb I know. I would of lost just 40 + the blind if I folded, but now 90 + the blind. He is a tight player, ussually aggressive,but today passive(not betting preflop with an AQ).
Heres the question: I understand the last move was dumb, but how should I of handled the flop and the turn?

Your cards matter, the cards on the flop/turn/river matter as well. Bet more on the turn. You don't even say what the blinds are so we don't know the size of the pot, which makes a big difference. Stack sizes also matter.

Post is changed.

Im guessing this is live play?