You can’t be an effective agent of change if you are angry. But you can’t just stuff down your anger either. You need to notice it and process it. Only then can you move forward in a positive way.
Think about what kind of results you want. You can practice accountability without animosity by holding the person accountable but giving them a way out. How can you get the results you want without backing yourself and the person into corners, behaving in a way that keeps you farther from your goals?
In the words of Thich Nhat Hanh “If someone is being unpleasant towards you or treating you badly, that means that they are unhappy. Accept that they are unhappy and treat them with love. Offer kindness without feeling superior, self-righteous, arrogant or smug. Do it with humility. Doing Metta meditation for them will help you internalize and truly experience your love.”