Good fold or am I just a nit?!

Hey all, sometimes I do think that I am too easily scared but in this hand I can seriously only put him on specifically JJ maybe KJ suited, but I can not think of anything else villain would have. Feel free to criticize my play at any point.

Villain stats
584 hands vpip- 20 PFR- 17 3bet- 6 FT3bet- 46 4bet- 3

I have QT spades in CO Villain is UTG

Player 1 posts the small blind 0.15
Player 2 posts the big blind 0.30
Villain raises to 0.75
Player 3 calls 0.75
Hero raises to 3.00
Player 4 folds
Player 1 folds
Player 2 folds
Villain calls 2.25
Player 3 calls 2.25

Flop: [8d 8s Jh]
Villain checks
Player 3 checks
Hero checks

I check here because even though I have a gut shot and back door flush draw I don't want to inflate the pot with 2 others when I don't think I am getting a J to fold and definitely not an 8 which they could both easily have player 3 more so an 8. Also that flop isn't very good for my range considering my 3bet. I may even check AA here... I'm sure someone will tell me if that's also stupid, but I think I would.

Turn: [As]
Villain checks
Player 3 checks
Hero bets 5.40
Villain calls 5.40
Player 3 calls 5.40

So with the As giving me a flush draw and open ended, neither opponent showing any sign of interest and the A being very good for my range I figured I would bet this especially as there are a lot of good rivers for me.

River: [3s]
Villain checks
Player 3 checks
Hero bets 13.50
Villain raises to 33.55
Player 3 folds
Hero folds
20.05 returned to Check456
Action has ended
Villain wins 50.85

With the 3s completing my flush draw and being checked to I have to bet for value, I'm thinking there could be 2 pairs, AJ, maybe just AK/AQ at this point I don't think I am behind, but when I'm jammed on I can really only think JJ most likely or KJ spades.

I can't think of any hands from an UTG opening range of a TAG player that checks this flop, flats turn and then check jams river. JJ's would raise pre and then just call a 3bet, I would probably 4bet them or fold if it was me, but this guy has a 3% 4bet so I don't think he's ever 4betting JJ. So calling makes sense to me. So does KJs both those hands would also check the flop after a 3bet.

The check on the turn also though, seems a bit weak to me, but what can just call my bet? JJ because it doesn't need to protect against any draw and even hopes I hit so flatting gives me that chance, Or KJs because it's drawing to the nut flush.

So the river is his perfect check jam card? I'm pretty certain he has JJ rather than KJ because even KJ has to be worried about me having JJ / AA / A8s so I would think KJs just calls my bet, and for that same reasoning I can't put him on a worse flush draw because not only are there FH's there are better flushes. Also, people at low stakes generally don't check raise bluff rivers.

Any feed back would be greatly appreciated or advice on where I could improve on how I played this hand. Or is this just a call and if he's got it he's got it, move on and get over it.