Antonio sees in his dream that he is dying , but to a different cause which can be reflected to Narciso dying from a gunshot. He sees himself dying because he might feel that he hasn't delivered what Narciso asked him to .
Antonio fears that the worst can happen to his family after Narciso's death, since the reoccurring sight of the Trementina sisters. This foreshadows that Antonio might have to do something against Tenorio and his daughters is he doesn't want his family to be harmed.
Antonio probably believes that there is some goodness in the world, which is represented by the golden carp. If he didn't see any good change in his dream, he believes that sooner or later they will change .