AK $25PL hand

I have been playing the $25PL games at pokerroom for about 2 months. (had no poker experience before that) I was up about $650, but recently I have had a downswing of nearly 4 buy-ins.

I have noticed that when I get involved in big pots, adrenaline takes over and I don't stop to think about my decisions. Because of that I just wanted to get some hands here to see what you guys think.

This is an AKo hand that I just had. The villain has been quite passive, calling a lot - but I havent seen him raise much. Seems pretty typical for a low limit player. After the flop I put him on a weaker ace - does anyone revise this assessment after the turn all in? Are my bets about right?

PL at pokerroom is not supported by the convertor so I will do the best I can to tidy it up.

Seat 1: rolandnohead ($7.50 in chips)
Seat 2: Villain UTG($20.50 in chips)
Seat 4: seanchamp ($1.25 in chips)
Seat 5: _zorro ($35.90 in chips)
Seat 6: dwearhawk ($33.30 in chips)
Seat 7: Hero [AS,KC] ($26.65 in chips)
Seat 8: Nussen007 ($25 in chips)
Seat 9: pollywin ($30 in chips)
ANTES/BLINDS
rolandnohead posts blind ($0.25), Nussen007 posts blind ($0.25).

PRE-FLOP
Villain bets $0.50, 3 folds, Hero bets $2, 3 folds, Villain calls $1.50.

FLOP [board cards AH,8S,6C ]
Villain checks, Hero bets $3, Villain calls $3.

TURN [board cards AH,8S,6C,9S ]
Villain checks, Hero bets $5, Villain bets $15.50 and is all-in, Hero calls $10.50.

RIVER [board cards AH,8S,6C,9S,10H ]