God’s word says "If possible, so far as it depends on you, live peaceably with all" (Romans 12:18). Evidently it is not always possible, but we should try.
The Bible gives us guidelines about confronting when we think we've been wronged (Matthew 18:15-17), and speaking the truth in love (Ephesians 4: 15). It tells us to confess our own sins (James 5:16) and forgive one another (Colossians 3:13).
So this prayer is not a substitute for any of that.
But years ago I wrote out a fairly lengthy prayer that I have prayed many times when I've had a "difficult person" in my life. I've found that praying for someone softens my heart toward them, and is part of God's plan to humble me and possibly (but not always) to heal the relationship.
This is a prayer specifically when the difficult person is (or claims to be) a member of the Christian family.
Maybe it will be helpful to you.