I feel that everyone much choose for themselves how to approach the idea of revenge. My personal feelings are easy and are born out of years of being beaten up on.
Pain- Pain is the root cause of all evil in the world. From war to crime, it all comes from pain. That includes hate. Everyone feels pain to some degree in some way. Plus it's not fair to spread pain just because you feel pain too. That's not fair to you or others. If someone slaps you, the first thing that you should do is not slap them back. That just continues the cycle of pain. When someone hurts you, remember that they are in pain too, the same as you. Knowing these things makes the next thing easier.
Forgiveness- Everyone deserves forgiveness. More importantly everyone wants forgiveness. From their friends, from their family and loved ones, from their community, from their God, maybe even from themselves. For small things, for big things. For things that no one knows about. For things that everyone knows but still causes you shame and hurt. If you want forgiveness, then you have to be able to give it. To show that you deserve it. To show that you understand. And no, it's not easy. True forgiveness hurts. Not because of the act of forgiving, but in forgiving you let go of a tiny sliver of pain that you've been holding on to. You, me, everyone is so used to holding on to their pain that they can't imagine themselves without it. After awhile it feels like letting a piece of yourself go, when really, it was just nothing at all.
You are not the splinters in your heart. They just hurt. Letting them out and letting yourself heal is hard, I know first hand. I have no magic here and I haven't learned the trick of making it not hurt myself. But it can be made to heal, slowly, like all wounds.
You can still love this person regardless. I love plenty of people who will never love me back for various reasons. We love not because we expect something in return, not even love itself. We love because we love. Love is it's own answer, like hope.