I feel guilty of not standing up?

I feel guilty of not standing up to early childhood bullying.

I was grade 4. There were 120 students in a batch with 4 classes of 30 students each. I was in 4-B. I hated my classmates and wanted to be in 4-A. I would go inside their main classroom during lunch break because I liked the people there. The ones in 4-B were not. There were 5 guys who would constantly tease me.They weren't physical or calling me names. They knew my fears and played it along with me. I never bothered to tell the teacher because If I told the teacher, I felt like the bullies will hate me forever. I really didn't want to be hated to. Because of Grade 4 i became I try-hard at making friends at Grade 5 and I became distanced. No one likes a try-hard. I had to change schools because I wasn't making good friends. At grade 6 that's when I restarted and made a friend, who was also in the same old school as me but we were never classmates. He would eventually be my best friend. At High School I had to realize I have to do the right thing and it's the bullies fault if they decide to hate on me for the rest of their life. I know like it wouldn't have happened (me and my best friend meeting each other) if I didn't stand up but.........I feel guilty of not doing it. I know it's a very long time but I have flashbacks of them once a year. 

TLDR. I feel guilty of not handling my childhood bullying because I thought I would be hated if I told on them.