Opp is 48/18/2.2 over 80 hands. What to do on the river? How are my flop and turn lines?

PokerStars No-Limit Hold'em, $0.50 BB (9 handed) Hand History Converter Tool from FlopTurnRiver.com (Format: FlopTurnRiver)

MP3 ($128.20)
CO ($12.70)
Button ($33.35)
SB ($27.80)
Hero ($47.50)
UTG ($47.75)
UTG+1 ($28.50)
MP1 ($12)
MP2 ($64.50)

Preflop: Hero is BB with 8, 3.
4 folds, MP3 calls $0.50, 1 fold, Button calls $0.50, SB completes, Hero checks.

Flop: ($2) 8, 3, T (4 players)
SB checks, Hero bets $2.5, MP3 calls $2.50, Button calls $2.50, SB folds.

Turn: ($9.50) K (3 players)
Hero bets $9, MP3 folds, Button calls $9.

River: ($27.50) 6 (2 players)
Hero sees that Button has about $21 behind and...