While painful memories are hard to forget.
This is a sentence fragment.
Whatever I have done on the past it may or may not define my future.
This isn't a valuable lesson, but a tautology. A weatherman who told you that it may or may not rain tomorrow would not deserve high praise, and neither does the self-help guru spouting similar bull excrement.
After 2 years, I met new friends who inspired me to be a special education teacher.
What does your teaching experience have to with memories, exactly? There are connections you could make, but you don't actually do so here.