Being bullied for 6 years

Hello!
It all started in 3rd grade — a boy was laughing at me for some reason but I just ignored him until he came and sit over next to me which made me nervous, He came over to me and he whispered in my ear commenting how ugly I was… every day he kept saying mean and rude things like that and started to make me believe.
Then in 4th and 5th grade more and more people boys and girls made me feel awful… calling me names, calling me ugly and stupid and ect. In 5th grade I had a year where I became popular and I was the one starting to become mean like the others and same as 6th grade, but the comments did not stop so I told my mom, dad and Principle but they didnt believe me… And a year later I am now still recovering from all of the mean comments and I have become depressed and sad and I still have visions whenever I see a locker or hear certain names or hear the topic of bullying I become very quiet and have 1 million thoughts run through my head. And I can still see and feel the pain that I felt on that day.