The God of the Bible is both just and merciful. God holds us accountable for how we live our lives, but also shields us with love to give us the opportunity to repair the consequences of our wrongs and choose a better path.
That to me is the overarching message of Psalms 103, which includes the lines:
Bless the Lord, O my soul, and forget not all his benefits.
He forgives all your sins and heals all your infirmities;
He redeems your life from the grave and crowns you with mercy and lovingkindness.
As human beings, we are all prone to making mistakes. But we do not have to allow our mistakes to drag us down into a hole of self-hatred and depression. Be sorry, but don’t stop there. Allow God’s grace to heal you from the negative emotions and behaviors that caused you to hurt someone else. Use that healing to help the ones you’ve hurt to heal. God’s lovingkindness gave you a new chance to be better; use that opportunity to be better to someone else.
Likewise, when someone who has harmed you makes an effort to make amends, accept that effort with grace. That effort may be imperfect. But allow it to be a step toward healing for yourself as well as the other person. It might not always work. Not every broken relationship can be repaired. But God keeps showing us mercy in our mess, and we should do the same for each other.