Set vs 1 card straight draw: 1/2 NL 6 Max

[mayday4379]

Villain is 60/20/.5 after a mere 17 hands. I'm 39/13/3. I easily cover villain.

Hero has 7 [img]/images/graemlins/diamond.gif[/img]7 [img]/images/graemlins/heart.gif[/img]
Hero Raises $4 in EP
2 callers

Flop ($14)
2,4,7 rainbow
Hero bets $8
2 callers

Pot $38
Turn: 6 completing the rainbow
Board: 2 [img]/images/graemlins/diamond.gif[/img],4 [img]/images/graemlins/heart.gif[/img],6 [img]/images/graemlins/spade.gif[/img], 7 [img]/images/graemlins/club.gif[/img]
Hero gets worried and bets $30
Villain calls, last guy folds

Pot $98
River: 3
Board: 2,3,4,6,7

Hero gets very aggitated and starts swearing.
hero bets $8
Villain pushes for $55 or so.

Hero Folds.

Here's my logic:
Preflop, I just wanted to raise it 1 bet from EP.
Flop: I wanted to send out a weak CB

Turn: Pay for the draws

River: I wanted to send a feeler bet out there. Maybe donish, but if I check and he pushes, i feel that I'm more lost than a reraise river bet. At these levels at the site I play on, I see very few reraises on the river with air. Villain was very passive, but only after 17 hands. Although maybe the $8 was too weak and I should've punched it up to $15 but then I think I force myself to call the extra $30 push from villain.

Where did I screw up?