How is hate caused by love and overcome by it when Juliet hears Romeo killed Tybalt in Romeo and Juliet?

Let us remember that Romeo has killed Tybalt, who is
Juliet's cousin, after he was married to Juliet. This of course makes the news of
Tybalt's death terrible to Juliet, and she expresses her horror and shock at the news
using a number of contradictions to describe her husband talking about how this act
reveals he is not what he appeared to be in terms of his outward
appearance:

O
serpent heart, hid with a flow'ring face!

Did ever dragon
keep so fair a cave?

Beautiful tyrant! Fiend
angelical!

Dove-feathered raven! Wolvish-ravening
lamb!

Despised substance of divinest
show!

Juliet continues in
this vein, but note how these contradictions express the confused emotions that she
feels. On the one hand, Romeo is her beloved husband, and on the other hand, he is a
hated killer who has robbed her of the lives of one of her family. Yet, after expressing
her confused feelings, note how her love for Romeo overcomes her hatred of him. When the
Nurse wishes ill upon Romeo, Juliet curses the Nurse, showing her love for her husband
and how this love has overcome any form of hatred she may
have:

Upon
his brow shame is ashamed to sit;

For 'tis a throne where
honour may be crowned

Sole monarch of the universal
earth.

O, what a beast was I to chide at
him!

Clearly, after having
been shocked by the news, she recognises that the power of love is more than equal to
the power of hate, and that love conquers all.