Exploitation of goodness

I am struggling with the impact of bullying I experienced in class. In an attempt to protect myself, I tried teaching my bully, believing that their behavior stemmed from ignorance. However, this only gave them more opportunities to bully me further, which made me feel weak and eventually led me to quit school.

Years later, I realized that I have been treated with brutality because I have never fought back. Consequently, I finally lashed out at someone, and this reaction left me under-confident and shameful. ​what could've been done difference?