Romeo repeats his request because Balthasar has remained silent. Balthasar's response suggests he is trying to keep Romeo calm: he maintains that Juliet is well, because she is at peace in heaven. Balthasar came by this news because he saw the funeral procession -- thus he does not know that Juliet's death is false.
By describing Romeo and pale and wild, Shakespeare hints that Romeo may be about to act rashly, without thinking. If Romeo had not rushed into taking his own life, the two of them might have lived happily ever after. However, Romeo is quick to act and does not take time to think that perhaps Juliet's death might not be real.