First, preflop. One player limped, CO raised, one cold caller. You have KQs and that's a 3-bet hand. Ok, CO wasn't opening the pot but iso-raised, so his hand is a bit stronger than if he just open raised. But both the limper and the cold caller make the pot more juicy so you have more incentive to resteal the pot.
After the flop you have an excellent draw. You aren't the preflop aggressor and you have a bad position. The board suits the preflop aggressor very well.
Don't bet into the preflop aggressor in such a situation. He has the range advantage and the nut advantage. Check and if he bets you can consider a checkraise.
As played you get raised all-in on the turn. Since you have only a draw it is now only a matter of odds and outs. The opponent is uncapped. It's highly likely that he has a set or a 2-pair. You have 4 clean outs to the nut straight (one of them is to the Royal Flush) and 7 other flush outs to the nuts. There is one more out to a flush (9:h) but this out could not be clean as it makes a possible full house. So that's 11 outs to the nuts and and one impaired out. You need roughly 3:1 pot odds to call this. 3:1 pot odds translates to 25% equity which is roughly what you have because of the outs. (11,5 outs / 46 unknown cards ~ 25%).
You need to call 1,80 for a pot of 1,80+0,86+2*0,28 = 3,22 which is worse than 2:1 pot odds. You can't call.
Unfortunately you have to fold.