the heart of the matter

Over the past day or so, it's become increasingly obvious that most of my current problems come from my inability to forgive one person's sins as they've had an impact on my life. I've known it at some level all along, but it's been made overwhelmingly clear to me how much I've failed to do so and how much I need to forgive.

Might anyone have any advise on how I can learn to really and truly forgive?

mille grazie