Dear Trillium,
That’s a pretty tough question, because it depends on the seriousness of the wrong. I don’t know how much background you have in catechesis, but there is a spiritual work of mercy called, “bearing wrongs patiently.”
If the matter is not so serious that your reputation is gravely damaged, it helps us to develop strong fortitude when we simply bear the injustice. Many of the saints have written about this, that we ought not to defend ourselves in these slight matters, for we grow in humility.
Now in the case of serious injustice, do you remember the story of Susanna in the book of Daniel? She was about to lose her life over the slander of the elders who falsely accused her. She trusted completely in God, who sent Daniel to prove these evil men were lying. Would it have helped her to confide in anyone else rather than trust completely in God? Vengence is mine, says the Lord. If he does not send a deliverer, then we bear the wrong.
These are two extreme examples above, neither of which may help you unless you are strongly attracted to living heroic virtue. OTOH, for those of us who are utterly practical, it helps to approach the person, for Sirach teaches us the benefit and wisdom of admonishment in Chapter 19:12-16.