One guy limps with a double stack utg, folds to me on the button, I raise to $5 with
![The Eight of Clubs [8c]](https://www.pofex.com/images/smilies/8c.gif)
Pot $16. Flop
![The King of Hearts [Kh]](https://www.pofex.com/images/smilies/Kh.gif)

Pot $48. Turn
![The Queen of Diamonds [Qd]](https://www.pofex.com/images/smilies/Qd.gif)
Pot $48. River
![The Three of Hearts [3h]](https://www.pofex.com/images/smilies/3h.gif)
I'm getting used to this kind of situation, where I have nothing on the end. I fold to a real bet, and I think about bluffing on the end if they check. But wtf to do here? That $5 bet looks like a blocking bet that's scared, but at the same time I would hate to pay another $40 or whatever and find out the guy won't fold his QJ or whatever. He's clearly a moron. Anybody bluff raise here? Anybody do anything different on any street postflop?
How many mistakes did I make here, anyway? Or is everything fine, and this is just a typical 6-max hand?