Juliet is increasingly at war with herself when she hears of Romeo's banishment. Upon hearing that he was banished for killing Tybalt, her first instinct is to rage against Romeo for murdering her cousin and lament that he deceived her and seemed so good and sweet when he was capable of such horrific deeds. She calls him a "damned saint, an honourable villain," suggesting that he is not the innocent she imagined him to be, but has both saintly and devilish qualities. This contradiction is greatly upsetting to Juliet.
However, as soon as her Nurse echoes Juliet's scolding of Romeo, Juliet is quick to turn and defend her husband. She curses her Nurse for wishing shame upon Romeo, claiming that "he was not born to shame: / Upon his brow shame is ashamed to sit." Having heard her own words repeated back from her Nurse's mouth, Juliet repents for having spoken ill of Romeo when she, as his wife, is the one who should protect and defend him before all others.
Juliet then tries to console herself, reminding herself that Romeo still lives and that though her cousin Tybalt is dead, he would have killed Romeo, making him a "villain" in her eyes. She asks herself, "All this is comfort; wherefore weep I then?" The answer is that news that Romeo is banished is worse than Tybalt's death.
That 'banished,' that one word 'banished,'
Hath slain ten thousand Tybalts.
Romeo's banishment is the greatest loss that Juliet can imagine, and her grief for him is equal to the grief she would feel if her entire family were to be killed, not just her cousin. She tells her Nurse that in losing Romeo, she might as well be dead herself and bids her to bring him to her one last time to say goodbye before he disappears.