PF and flop are standard. I raise the turn. There are two possibilities here: villain believes that you have the K, and can beat it, hence the donk bet on the turn. Secondly, villain doesn't buy that you have the K (many players would bet as you did on the flop), and improved with that J. The first scenario is unlikely, as the c/r would be the better move, though without reads, it's tough to make that judgement. The second scenario is considerably more likely, and either you've got villain outkicked, or you've run up against two pair. I think you're likely to have the best hand, and should raise, but fold to a 3-bet. Call or bet the river. As you played it, the river is fine.