We must have been through something bad in the past, let's say you are getting hates from people around you, you are betrayed by your partner in your relationship, you make mistakes, you failed and this were all happened in your past. You either let these darkness of your past become your lesson or you let these darkness become an excuses or a reason for you to make a second mistake again.
I know it much seems like it is not even your fault, for being betrayed by your own partner in your relationship, getting hates from everyone, yes, it is not your fault at all. But does not means it is not even your fault, then you are doing these things to other people.
I had been meeting a lot of people, who ruined their-selves because they had been using their past to be their excuse. What kind of excuse? Well, people tend to holds on grudges for what they have been through in the past. The thought of, "I had been through worst, so people need to face it too." The unfairness happens in their heart will lead them to the deeper darkness. They are not healing, but they are digging the wound deeper.
What happened in the past, should not be a reason or an excuse for you to do it to another human being. Being bullied in the past, and by satisfying your own desire, you do it to another person. It would not solve anything or you would not heal from your past, but you are letting the chain of darkness continues. Let be your past be a lesson for you, if you are getting hates before, do not hates other people as you know how it felt to be hated by people around you, if you get betrayed by your girlfriend of boyfriend, do not take it as a reason for you to hurts another human being just so you are thinking that it is never been fair for you to ever face something like this, alone.
Everything happens in life actually being planned by God. We are living His story, not our story. Our life is all about God, we are just the brush that God uses to paint the picture. So accept what happened in your life, good or bad, it is a lesson. Always take everything in life as a lesson for you. While it comes to fairness, well, fairness should be something good but it is getting toxic nowadays. People are using this honorable word of fairness to say "well, it is never been fair for me to face this alone, everyone need their lesson too." We need to stop this kind of thought as it is so toxic for people who is innocent. Just remember, everyone will have their own lesson, we are sinner, we are meant to be taught, we are meant to receive lesson, it just, God decide it all.