EWTN Catholic Q&A
Question from James Blamnchard on 10-19-2017:

If Jesus tells us to forgive. What if I am not able to forgive a man who abused my daughter and another who abused my son?

Answer by David Gregson on 02-01-2018:

"Ought implies can." In other words, we're not held responsible for not doing what we can't do. However, the ability to forgive is something to be striven for. We hope for forgiveness of our own many sins, and though they may not seem as great as those we're asked to forgive, in the eyes of God what seems small to us may be great in His.

I suggest praying for the grace to forgive. It's an act of the will, which the emotions may not support. I would just avoid stirring up the emotions by dwelling on the evil done to your children, and dwell instead on the mercy God has shown to you.