How do you cope with injustice? Evil people seem to get away with their crimes

Long story short, I was physically and emotionally abused by a teacher I trusted when I was 16. This went on for 3 years.

To the point where I have permanent and obvious scars all over my body, and likely suffering from PTSD now. I also developed several chronic illnesses and mental disorders from the torture I was forced through. It destroyed my health, my body has never been the same since then.

Reported the teacher after I graduated, but the school did nothing much and she still works there.

She was the head of the course and enjoyed power tripping on me behind the scenes.

Seriously, how does one even get over trauma and injustice like that? How does you cope with the fact that evil people get away with hurting others?