Rio Big O Cash Gaming

5/5 Big O
effective stacks: 1000

6 handed. This occurred 2-3 hands after sitting down.

Hero dealt: Aj532 rainbow
mississippi straddle on the button to 10.
hero completes in SB
CO: raises to 50
hero calls

(110 in pot - 2 players)
Flop: 554 two tone (hero does not have flush draw)
hero: checks
villain: checks

(110 in pot - 2 players)
Turn: 554k completing flush draw
hero: checks
villain: bets pot (110)
hero: calls

(330 in pot - 2 players)
River: 554k8 4 flush on board
hero: checks
villain: bets pot (330)
hero: tanks, then folds

Analysis:
Preflop: This seemed ok, even though hero does not have suit.
Flop: Hero was attempting to c/r here with gutshot nut low wrap + uncounterfeitable low. Although hero would be in bad shape against A2 with flush draw, hero has a huge amount of equity.
Turn: Hero is now lost. Should hero just call down multiple bets? RIO are kind of bad and it's either call turn/river or fold turn.
River: Based on turn action (check/call), Hero should never fold the river as hero may be getting 3/4 sometimes on a bluff. More likely, villain is chopping with hero.

In summary, hero made mistake by check/calling turn, but then folding river.