The 37-year-old actress withdrew her name from awards consideration claiming that her storylines did not warrant a nomination.
But eight years later, Katherine admitted she made a huge mistake and needed professional help to get over the criticism she endured over her actions, reported Femalefirst.
"I didn't feel good about my performance and there was a part of me that thought, because I had won the year before, that I needed juicy, dramatic, emotional material," she said.
"But I was really embarrassed. So I went in to show creator Shonda Rhimes and said, 'I'm so sorry. That wasn't cool. I should not have said that'...I shouldn't have said anything publicly but at the time, I didn't think anybody would notice."
"I had never done therapy until a couple years ago. I started going because of the scrutiny. I was not handling it well. I was feeling completely like the biggest piece of ... on the bottom of your shoe.
"I was really struggling with it and how to not take it all personally and not to feel that there's something really deeply wrong with me.