How to forgive and became as I was before getting hurt?

[Real Princess]

I need advice please? 

I misunderstood my Daddy two years ago. I thought my Daddy was silent to them who bullied me. My Daddy's silence was not his support. Here I misunderstood him. I was in dark for last two years but my Daddy remain there were he was always for me. 

Everything is fine between us now, but he asks me often that why am I not jolly like previous days before those idiots hurt me? Being the luckiest girl in the world, why I can't forgive those moments? 

Can anyone help me? If yes, please feel free to share your thoughts.