Is there any reason why nobody seems to put the villain on AKs or AQs in diamonds? That gives him two overcards to the queen with AK, or top pair with the AQ, plus a nut flush draw.

The fact that the hero only called the pre-flop bet means he doesn't have kings or aces, but he could have put you on JJ or some high cards combination.

And his raise to 7,50 $ after the turn looks more like a value-bet than a tentative to scare you away from the pot.