You should know that whatever situations you are currently undergoing in life is because of your Prarabdha Karma (Karma that bears fruit in the present). And whatever you deserve, you will surely get that in life.
Getting a friend or enemy happens through some karma. So if your time is good, even an enemy acts like a friend, and if your time is not good, even a friend acts like an enemy.
Whoever does something wrong will surely have to repent and pay for it. That is his Karma and he has no choice.
Saying, "My suffering is due to that person", will continue the karma because that impression will be there in your mind. Why are you not looking inside? Why are you not moving on? Why are you holding onto an event of the past and blaming the other person for your karma? If you do this then you will continue to be miserable.
If you are suffering, it's not because of somebody, it's because of you only. You better suffer and get rid of it. Instead of that, if you say, "That person is responsible for my suffering", then you are making more karma and carrying it on to the next lifetime. But if you say, "My suffering is because of me, and I take ownership of the karma", then you become free.
When you get hurt, it's your karma. You must have hurt somebody sometime and so you got it back now. Nothing happens without a reason. This is the highest knowledge.
Know that you are pure and your heart is clean. In the company of the pure you are also purified. All your past karmas are dropped.
When someone blames you, they actually take away some negative karma from you. Understand this and don't put up resistance. Feel happy and lighter about it. Outside you may resist, but inside if you don't resist, and feel happy that somebody is there to blame me and take some negative karma, you will feel immediately lighter.