I lied about my father being abusive when I was younger. How can I repent?

Salaam. When I was in high school I used to cut myself for dumb reasons (sympathy? attention?) and I would tell friends that my father was the one who had done it and they thought he was abusive. It's been close to 10 years since then, and I'm extremely ashamed of what I did as my father is a great man. Islamically, what do I have to do to be able to right this wrong other than making dua? Is it required for me to find/reach out to people in high school to tell them I had been lying about my father? Is this something I need to tell my father I did awhile back? May Allah forgive me