How do I teach my kids about forgiving others when I'm angry

My 8 year old wouldn't apologize to his sister and I blew up. Literally told him off in front of everyone about how he needs to be like Jesus and forgive and show love. Soon as the words came out I realized I was yelling about forgiveness which is pretty hypocritical. How do you guys handle moments where your kids need a lesson but you're too fired up to teach it right? Feels like I'm failing at this whole example thing.