Poker another weird hand...?

So there are 2 limpers 1 from UTG plus 3 and one from the high jack. They both have 75 big blinds. I'm in th small blind with 75 big blinds holding kk. I raise to 2400 (. 4x the big blind). The UTG plus 3 guy calls me and the flop comes 10. 6 3 rainbow. He min raises donk betting 600. I feel I can slow play my hand by smooth calling and making my move somewhere else I call. Turn comes 8 hearts so 2 hearts on board. He min raises again and i decide to raise to half the pot bring 4k - as i feel if I smooth call the max value out of my hand would be decreased as now if the board pair or a heart or ace comes I'd be representing one of them cards. To my amazement he min re re raises me 4 betting to about 7,200. I call feeling that he's either got 2 pair so I want to keep the pot small or I feel if I have the best hand I can call a half pot bet on the river or bet half pot if he checks to me depending if the river is an ace or not... River comes a 8 and he bets the pot being 23k which is neally him going all in as he has 7k behind. Now I'm very confused. It doesn't look like a value bet as I've shown far to much weakness throughout the hand and I feel he prob has a busted straight flush draw j9 hearts.... After a lot of thought I pay him off, he shows 89 spades..... Was my river call bad in your opinion? What do you guys think about the hand...?