Burying the hatchet and forgiving someone for something they have done to you can be difficult for anyone. 
Holding grudges and anger toward another really does wear you down both physically and mentally. When you forgive someone, you are really doing it for yourself not for the other person. Forgiveness helps you excel and move to the next level. Holding grudges is one of the unhealthiest things a person can do.
You will fee a sigh of relief once you have done this. Harboring anger and bad feelings toward others wastes energy that you could be using doing something productive and constructive. 

 “I think joy and sweetness and affection are a spiritual path. We’re here to know God, to love and serve God, and to be blown away by the beauty and miracle of nature. You just have to get rid of so much baggage to be light enough to dance, to sing, to play. You don’t have time to carry grudges; you don’t have time to cling to the need to be right.
- author Anne Lamott, in a recent interview.    
 (Source: The Washington Times)”

forgiveness definition
for·giveness (fər giv′nis)
a forgiving or being forgiven; pardon
inclination to forgive or pardon

forgive and forget phrases / idioms
Both pardon and hold no resentment concerning a past event. For example, After Meg and Mary decided to forgive and forget their differences, they became good friends. This phrase dates from the 1300s and was a proverb by the mid-1500s. For a synonym, see let bygones be bygones.

1. "Forgiveness does not change the past, but it does enlarge the future." - Paul Boese

2. "You will know that forgivenss has begun when you recall those who hurt you and feel the power to wish them well." - Lewis B. Smedes

3. "The weak can never forgive. Forgiveness is the attribute of the strong." - Mahatma Gandhi

4. "Genuine forgiveness does not deny anger, but faces it head on." - Alice Miller

5. "You can't undo anything you've already done, but you can face up to it. You can tell the truth. You can seek forgiveness. And let God do the rest." - unknown

6. "We achieve inner health only through forgiveness - the forgiveness not only of others but also of ourselves." - Joshua Loth Liebman

7. "Inner peace can be reached only when we practive forgivenss. Forgiveness is letting go of the past, and is therefore the means of correcting our misperceptions." Gerald Jampolsky

8. "Forgiveness is the sweetest revenge." - Issac Friedman

9. "Forgiveness is the mightest sword, is the highest reward. When they bruise you with words, when they make you feel small, when it's the hardest to take.....you must do nothing at all." - Jane Eyre

10. "It's toughest to forgive ourselves, so it's best probably to start with other people. It's almost like peeling an onion. Layer by layer, forgiving others, you really do get to the point where you can forgive yourself." - Patty Duke

 11. “Not forgiving is like drinking rat poison and then waiting for the rat to die.”
Anne Lamott