Well this is difficult! We are only human after all. However, there is absolutely nothing more satisfying than honestly praying for the well being of someone who hates you. Try it as the sun rises.

Matthew 5:43-45
“You have heard that it was said, ‘You shall love your neighbor and hate your enemy.’
But I say to you, love your enemies, bless those who curse you, do good to those who hate you, and pray for those who spitefully use you and persecute you,
that you may be sons of your Father in heaven; for He makes His sun rise on the evil and on the good, and sends rain on the just and on the unjust.
Bible Gateway passage: Matthew 5:43-45 (NKJV)