Leading the river was a mistake. Your J-high flush is nothing but a bluff-catcher at this point. It is the only way to make money with it. You either get a fold or a raise, nothing in between. With position, you could make a really tiny bet with it, like $5 after a check, and that's it, but you should check behind most of the time because you can't stand being check-raised. You need a cheap showdown with a J-high flush on that board.