2/4nl. I'm in the sb

it's a nice limping table and i have doubled my stack over about an hour or so. Have been playing LAG and been caught bluffing a couple of times in smaller pots.
4 players limp and i complete and the BB checks.
Flop =

All check to the button who raises $12, button has been fairly tight and conservative but has raised in position fairly consistently when the opportunity has arrived. He has about $700 to my $800.
I decide to raise to test him out and raise to $36
All fold to the button who flat calls
Turn =

I lead out for a 2/3's of the pot $72 and the BB re raises another $72, now i am confused and thinking A7, A8 or possibly a medium flush
I call the $72 and hope for a club on the river.
River =

I lead out for $120
He thinks for a minute then shoves it all in leaving me about $400 to call
Can i fold?
Would you have played it any different?
Whats he got?