I use to worry about whether I won or lost but now I worry more about whether I played the hand correctly. Is that a good thing?
YES. this is the BEST thing.

try not to make a habit of completing hands from the SB, position is the most powerful thing in poker, and Kq isnt a good hand to play oop, but your 4 handed so i guess its ok to raise this from the sb to get a slaggy steal.
as played i pot the turn and,c/c any small sized bet, fold to a psb or bigger. the flush hit and its pretty obvious why hes calling u down, so dont showdown unless u have good odds.