str8 vs big river overbet

[Shes92]

Fold river here??? Villain is 31/7/0.7 after 170 hands. Looking back I strongly believe I should have bet out on the turn or check folded but what actiuon should I take on the river. I felt he had a flush but the huge overbet confused me.

Absolute Poker
No Limit Holdem Ring game
Blinds: $0.50/$1
6 players
Converter

Stack sizes:
UTG: $52.20
UTG+1: $199.20
CO: $78.80
Button: $104.25
SB: $114.65
Hero: $116.45

Pre-flop: (6 players) Hero is BB with 4[img]/images/graemlins/spade.gif[/img] 4[img]/images/graemlins/heart.gif[/img]
UTG calls, UTG+1 folds, CO calls, Button folds, SB calls, Hero checks.

Flop: 6[img]/images/graemlins/club.gif[/img] 7[img]/images/graemlins/diamond.gif[/img] T[img]/images/graemlins/spade.gif[/img] ($4, 4 players)
SB checks, Hero checks, UTG checks, CO checks.

Turn: 3[img]/images/graemlins/spade.gif[/img] ($4, 4 players)
SB checks, Hero checks, UTG checks, <font color="#cc0000">CO bets $3</font>, SB folds, Hero calls, UTG folds.

River: 5[img]/images/graemlins/spade.gif[/img] ($10, 2 players)
<font color="#cc0000">Hero bets $5</font>, <font color="#cc0000">CO raises to $43</font>, Hero ??