What does forgiveness of Nparents look like?

My school had a speaker today who went on about forgiveness for forty minutes. If you can't forgive, you're carrying around bitterness in your heart and letting it define you, and you have to forgive those who have wronged you and pursue healthy relationships with them.

What about relationships where one of the people contributes nothing and only takes away and causes pain and refuses to admit any wrong?

I'm so conflicted and triggered as fuck right now. I feel like I'm going to vomit. Help and thoughts?