I would like to recommend the book, “Unpacking Forgiveness: biblical answers for complex questions and deep wounds” by Chris Brauns.  In this book he gives some helpful suggestions to deal with the very real issue of bitterness.  I will highlight some of these suggestions here.The Apostle Paul writes some helpful words in Romans 12:17-21 that apply to the issue of bitterness and if applied to your life will help in overcoming bitterness.  First, as difficult as this may be and as contrary to how you feel, resolve to not seek revenge.  “Do not repay evil for evil”, Romans 12:17.  Second, proactively show love, Romans 12:20.  Loving those who have hurt you is counter intuitive to our nature but it is so like Jesus.  Third, wait for God’s justice and trust in his sovereign control, Romans 12:19.  You can take your hand off of this situation knowing that God ultimately judges sin and he is in control of your life.  As you contemplate these wise and life giving words you will find that they will help you deal with bitterness.You should also confess before God what bitterness is, it is a sin.  As challenging as the circumstances of our lives can be at times, bitterness is not something that is done to us but it is a response that we choose to live with.