50NL - River two pair and get donked into

[bazooka87]

Ok, pretty sick spot. Villain running at 34/17/1 over about 200 hands. I'd been raising a ton from the button into his bb and his fold bb to steal was 60, and I'd taken it down almost everytime with a cbet so I think his flop donk was an attempt to combat this, and naturally I raised it as all donkbets can be folded if raised (I know this isn't true, but so often it works). Turn bet is very very marginal I admit, but ehh not really concerned about that.
What am I to do?

PokerStars No-Limit Hold'em, $0.50 BB (3 handed) Poker Stars Converter Tool from FlopTurnRiver.com (Format: 2+2 Forums)

SB ($149.10)
BB ($43.25)
Hero ($72.80)

Preflop: Hero is Button with T[img]/images/graemlins/club.gif[/img], 8[img]/images/graemlins/spade.gif[/img].
<font color="#CC3333">Hero raises to $2</font>, SB calls $1.75, <font color="#666666">1 fold</font>.

Flop: ($4.50) 9[img]/images/graemlins/club.gif[/img], 3[img]/images/graemlins/diamond.gif[/img], 5[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">SB bets $2.5</font>, <font color="#CC3333">Hero raises to $7</font>, SB calls $4.50.

Turn: ($18.50) T[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(2 players)</font>
SB checks, <font color="#CC3333">Hero bets $11</font>, SB calls $11.

River: ($40.50) 8[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">SB bets $27</font>