Well, I should win a pawn now, but I'm not really happy. Either I played sloppily (18. ...Rb8 and 19. ...Bxd2 don't seem so good now) or I thought my position was better than it actually was.
Namely, if I am forced to exchange the Queen, my extra pawn might not matter bc of the opposite-squared bishops. My only consolation is that I might be able to pick off his other a-pawn (he cannot advance it to a6).
I think he just dropped a second pawn for no reason, but the sad thing is, this might still be a draw. I can't wait to turn on the engine to see where did I **** up.