1010 in a tough river spot

Every player in this hand is pretty bad. The first two limpers are horrendous, and the button is a tight-ish preflop player (25%) but majorly overaggressive postflop. The reason I just called preflop was to be able to CR the field on a low card board, as the button would always bet if checked to him.

Party Poker 15/30 Hold'em (10 handed) FTR converter on zerodivide.cx

Preflop: Hero is SB with T[img]/images/graemlins/heart.gif[/img], T[img]/images/graemlins/club.gif[/img].
2 folds</font>, UTG+2 calls, 1 fold</font>, MP2 calls, 2 folds[/i]</font>, Button calls, Hero completes, BB checks.

Flop: (5 SB) 2[img]/images/graemlins/club.gif[/img], 6[img]/images/graemlins/spade.gif[/img], 7[img]/images/graemlins/spade.gif[/img] 5 players)</font>

Hero checks, BB checks, UTG+2 checks, MP2 checks, Button bets</font>,Hero raises</font>, BB folds, UTG+2 folds, MP2 calls, Button calls.

Turn: (5.50 BB) J[img]/images/graemlins/spade.gif[/img] 3 players)</font>
Hero bets</font>, MP2 calls, Button folds.

River: (7.50 BB) 4[img]/images/graemlins/heart.gif[/img] 2 players)</font>
Hero bets</font>, MP2 raises</font>, Hero ...