UTG's VP$IP is 30. PFR% is 2, and PF of 2.14.

should i have mucked the turn and saved $20?

PokerStars No-Limit Hold'em, $2 BB (7 handed)

SB ($33.55)
BB ($248.35)
UTG ($181.10)
MP1 ($75.55)
MP2 ($199.60)
Hero ($390)
Button ($112)

Preflop: Hero is CO with , .
UTG calls $2, 2 folds, Hero raises to $10, 3 folds, UTG calls $8.

Flop: ($23) , , (2 players)
UTG checks, Hero bets $18, UTG calls $18.

Turn: ($59) (2 players)
UTG bets $20, Hero calls $20.

River: ($103) (2 players)
UTG bets $48, Hero folds.

Final Pot: $147

Overcard AND flush hit the turn. I most likely let him have it when he leads out.
Calling the turn just to fold the river doesnt make much sense.

Either fold, or raise somewhere. I prefer the fold.

I think you have to raise or fold on the turn, calling is the worst possible option, folding definetely best. If you raise and get called you're obviously done with the hand. His PFA is not that hight so it seems unlikely that he would bet anything you can beat and your hand looks like crap after that turn card arrived.

What's he going to bet with that you can beat? Gotta fold the turn.

But damn it's hard to do that, isn't it?

I have a new theory. (Actually, I'm sure it's not new, but it's new to me.) If you have been raising and betting and getting called, and then somebody bets into you or raises you when you don't expect it, it's very difficult to go from "bet-raise-bet" mode into "fold" mode right away. It is too far to go all at once. Even if you are pretty sure you're beat, you don't want to make that sharp 180 degree turn. So I, at least, tend to go into "call" mode once and then fold only once they bet again. It takes two separate steps, and I can feel the disappointment building inside myself, at each step: from "bet" to "call," then from "call" to "fold": "darn it," and then again "darn it."

I wonder how much money I waste not being able to fold hands like this one on the turn.