Resentment versus forgiveness? That was a choice I faced after my divorce. I chose forgiveness but it wasn't easy and it didn't happen right away. I had to wallow in resentment for awhile which only added to my misery.
A great movie about resentment is "Grumpy Old Men". They make a comedy out of it but really, the feud takes up every bit of energy from the two main characters. It is a lesson about resentment being consuming, stupid and a poor choice.