How can a sensitive person ever get over the amount of abuse and injustice suffered throughout their life?

The best way to start coming out of this is to find a way to help others that suffered as you have. Find community service projects that give you a chance to help them because you understand. This will help you to stop looking inwardly and more outwardly. People that hurt others are insecure. They put someone down to make themselves feel better. If they put you down then you must have been above them to start with.