Many people have been betrayed, hurt, some even traumatized by others. Or by hard situations, circumstances and environments. This birthing a lot of loneliness, hatred, anger, depression and many other vices.
I don’t know your story, or what could possibly be the source of the bitterness within. What I can say is that, as much as you want to move on from your past. Away from that person, away from those taunting memories. You are trying in vain, if you still hold grudges and still wish for revenge on the other party. That caused you harm.
This is by no means insinuates that you don’t need justification. However, one who wishes to live a happy and fulfilled free life. One needs to be of a clear conscience and have a pure heart, one without blemish. You may have reasons to be angry at someone. But that does not imply you should repay them with the same measure they hurt you. Revenge may sound like sane justice but it’s not the way of the Lord.
If you are a believer, don’t forget that Christ urges you to forgive and love your neighbor as yourself.
But why would He expect you to love people who have hurt you?
Just look at Christ, the only Son of God initially. Right before Him was the law through Moses. However Israel failed to adhere even to one single one of them, the laws. They failed to keep even one law in their lives. With all their sin and divergence from God’s will, Christ still saved them. While you were still a sinner, Christ died for you, me and every other believer. This is love. Love that keeps no record of wrongs, love that forgives.
Parable of the unforgiving servant
Therefore the kingdom of heaven is like a certain king who wanted to settle accounts with his servants. 24 And when he had begun to settle accounts, one was brought to him who owed him ten thousand talents. 25 But as he was not able to pay, his master commanded that he be sold, with his wife and children and all that he had, and that payment be made. 26 The servant therefore fell down before him, saying, ‘Master, have patience with me, and I will pay you all.’ 27 Then the master of that servant was moved with compassion, released him, and forgave him the debt.
28 “But that servant went out and found one of his fellow servants who owed him a hundred denarii; and he laid hands on him and took him by the throat, saying, ‘Pay me what you owe!’ 29 So his fellow servant fell down [e]at his feet and begged him, saying, ‘Have patience with me, and I will pay you [f]all.’ 30 And he would not, but went and threw him into prison till he should pay the debt. 31 So when his fellow servants saw what had been done, they were very grieved, and came and told their master all that had been done. 32 Then his master, after he had called him, said to him, ‘You wicked servant! I forgave you all that debt because you begged me. 33 Should you not also have had compassion on your fellow servant, just as I had pity on you?’ 34 And his master was angry, and delivered him to the torturers until he should pay all that was due to him.
35 “So My heavenly Father also will do to you if each of you, from his heart, does not forgive his brother [g]his trespasses.”
We see that Christ expects each of us to forgive one another. Not because your wrong has been justified, but because He forgave you more. He paid for your life. Now by what measure is a single offense from your brother/sister greater than the sins God has forgiven you?
Moreover when Jesus was asked by Peter, ‘how many times shall you forgive?’ This is what he replied in Matthew 18: 21-22 NKJV
21 Then Peter came to Him and said, “Lord, how often shall my brother sin against me, and I forgive him? Up to seven times?”
22 Jesus said to him, “I do not say to you, up to seven times, but up to seventy times seven.
Those are the number of times you should forgive those who offend you. As for revenge, justification, that is the Lord’s duty. Not yours.
Beloved, do not avenge yourselves, but rather give place to wrath; for it is written, “Vengeance is Mine, I will repay,” says the Lord.

Love covers all sin and it is the greatest of all. Love keeps no records of wrong. Love perseveres. Love is what sets you apart from the rest. By love you were set free, and in the same manner, as one who received freely. So should you freely give.
For what benefit shall derive from paying them back with pain?
Happiness? More anger? A gratified sense of fulfilment? Justification?
None of the above have an everlasting peaceful ending, if done out of revenge. All it emerges are more contentions and wickedness. But why bother with all this, when you have one who can take revenge on your behalf?
Let God do the justification. As for you, concentrate on what matters; following the will of God.