He show AK and promptly hits straight on river....
I call and he shows 67 off, 7 on the flop and another on turn....
Sounds like you were only losing to Bad Beats. This is how it should be - nothing wrong with your play as I see it, just the bad luck that sometimes happens and the knowledge that in the long run you win and these donks lose.
worked out nice for you but pre flop you raised an amount that he had to call, if the flop has a card higher than a J and he bets ( both v likley ) then you are in trouble