You are the only one to answer this question - with the given information.

First of all, I'd suggest to not name your opponent a fish - but give him attributes: "a weak player that is too passive preflop, overvalues high cards, does not like to fold but does not bluff often (enough)". Something that way would make it possible to give a meaningful answer.

Preflop: I don't know your preflop range but I guess you 3bet TT+, AJ+, KQ and KJs. When you are playing against a fish I wouldn't have a polarized range with many bluffs (because you have less fold equity against his wide flatting range so I would add the top of my calling range to my 3betting range (additionally: ATo, A9s, A8s and some broadways).

Postflop: Flop = clear call, Turn = call should be okay, fold would be also okay against a passive fish(because the the bet is compared to the board relative small)
River: Why are you leading this river? (You didn’t improved and you want get value from worse hands) In my opinion a clear fold (when the fishes bets on the river). We have so many better pairs KX and also some flushes etc. in our range.

The lead on the river shows a fairly strong lack of understanding of the game and why you bet.

But by posting this hand it seems that you are onto that so !. Good job. The first step is figuring out where the mistakes and inconsistent thought patterns lie. The next step is doing something about it.

In this hand i realised my mistake. Its one of those things where i know why it was bad but it was like a frustrated blocker bet. Simply put in that spot worser hands are only folding and better hands calling. I just had to post my hand here so i can be reminded by RIO lol and also get diciplined by other better players to stop making rookie mistakes.

Why not bet flop? You raised pre. If he has worse hand you want more money in thet pot. If he has stronger you dont want him to know that. Do you only bet when it hit's your hand? Or don't you cbet? Do you hope that he will bluff this flop pretending to have a K? Why wouldnt he have a K? VIllain clearly understood you had a weak hand and bet small to milk you for some value. If you had bet the flop he might even have raised saving you lots of money. Only thing I'm surprised is he didnt raise you small on the river. Your betsizing pretty much screams please let me see a cheap showdown (Unless you are being really tricky). I think even all in would have been better EV

But when you check every time he might also think you have nothing or low pocket pair, so he might double or tripple barrel with nothing too, just cause he know your hand are weak

Anway I would fold turn depending on player type. I think this one is pretty tight

I checked qq here because i also check ak sometimes in this spot