Cara Mia, if that man has not separated you from the love of God, and he has not, then the only thing keeping hate of him alive is your thought about him. Only your pride keeps him in your memory. Dissolve your pride, and you dissolve your hate. To be still possessed of the hate that pain made is not intelligent. Take care. It can sap your energy to what you know to be your purpose. By being troubled about it, you have already discovered it to be unworthy of your grander aims, and that is the beginning of humility.
It would be far more constructive if people tried to understand their supposed enemies. Learning to forgive is much more useful than merely picking up a "stone" and throwing it at the object of one's anger, the more so when the provocation is extreme. For it is under the greatest adversity that there exists the greatest potential for doing good, both for oneself and others.