I can't decide if i played this hand correctly at all, should i have bet harder, should i have made a crying call?

PokerStars No-Limit Hold'em, $2 BB (9 handed) FTR converter on zerodivide.cx

Hero ($221.50)
UTG+1 ($199.80)
MP1 ($76)
MP2 ($546.80)
MP3 ($143.80)
CO ($324.40)
Button ($265)
SB ($214.60)
BB ($200)

Preflop: Hero is UTG with J, A.
Hero raises to $6, 2 folds, MP2 calls $6, 1 fold, CO calls $6, 3 folds.

Flop: ($21) Q, A, J (3 players)
Hero bets $8, MP2 folds, CO calls $8.

Turn: ($37) 2 (2 players)
Hero bets $12, CO calls $12.

River: ($61) K (2 players)
Hero bets $12, CO raises to $36, Hero ...