Do you have to fold here?

[BluffTHIS!]

Even at a higher stakes table, that would have played out for me just the same because of the relative stack sizes. However if both of you had very deep stacks then just a call would have been in order, despite that fact that normally you are going to beat both other players on that board. Just be glad you had more money than the SB to win off the fish and lower your loss.