What would happen if you went to person who offended you and had a conversation. And no, I don't mean yelling, accusing, or whatever else might be your first instinct. I don't mean going on and on about what they've done wrong and simply expected them to accept that. A conversation is "an exchange," which mean both of you talking.
Go to person you are frustrated with. Tell them you know there is a problem but you don't want it to come between you. Let them tell their side of the story first, without interruptions. Put yourself in their shoes. Apologize for whatever you have done wrong, even if you don't think it was that bad.
When it is your turn to speak, be calm. Don't go into accusatory mode. As soon as you start blaming them for everything, it will all go downhill. Explain what they did that bothers you so much, and give them a chance to share their feelings and apologize.
Gossip and blame don't fix the problem. You have no idea what effect your words will have. Talk to the person, not about them. Loving conversation is what repairs relationships.
Just talk... and listen.