My best friend bullied me

I had a “friend” since I was in kindergarten. Now I am in 5th grade. He was bullying me ALOT. Then it came to the point that I wanted this to stop. He has been bullying me for the last 3 years since 2nd grade. So over summer break, I decided to talk to him. He did not listen. I tried 3 more times and he did not listen. So I wrote a letter to him. The letter said how many ways he had bullied me. I am in cub scouts, so I left that group and went to a new cub scout group away from where he was. I also had a friend who went with the one who was bullying me. After I wrote a letter to both of them and sent it I felt better for a little while. Now they are out of my life but still come to my thoughts once and awhile.