very borderline calls preflop and on flop IMO... seems like they just kept feeding you barely enough to stay in...

flop your looking at 9.5 to 1, for your gutshot/bd flush/ and the possibility of one of your overcards being good (very slim)

i would've tried to get away preflop most of all, and dumped it on flop with all that action as well...

once you got as far as the turn it seems fine to me, even though you're clearly beaten, 16 to 1 is worth a call w/ your rivered top pair