kindergarten bullying

i joined kindergarten when i was 4, a year after most people would join kindergarten. when i joined, my whole class started bullying me but i don’t know why. some physically bullied me like pulling my hair, or pushing me etc, while others were extremely mean to me and me only. i had no friends, except for 1. they also verbally bullied me. i used to cry everyday after school and always told my mother about it till my sister called me a ‘complain queen’ so from then on i didn’t cry, i didn’t say anything about it. my mother didn’t do anything about it despite the times i did cry and complain . i survived the bullying for 3 years. when someone mentions the word “kindergarten” i’ll get really angry and upset and it’ll just spoil my whole day. kindergarten was hell.