How do I stop myself getting really upset and angry when my sister calls me horrible names?

1. whats the age difference? well most siblings decide to wind up the smallest sibling (guessing ur smaller than ur sister) but my siblings are different sum times there jokin but most of the time its always been moaning at me constantlly and calling me stupid or retarded or mentally challenged if i forget to do something and my mum didnt help either ( which leads to question 2 ) because of my whole family it leaded to me bumking skool also bcuz the kids at my school didnt help either which then leaded to my head of yr making a councellors apoint ment and i have to say it makes me feel so much better and it is gr8 to talk about how you feel thy even hav a punching bag and also we talked about what they do to me how my nephew (17) me (13) never respects my privacy mostly bcuz of his size advantage things weve talked about made me see my things in a different wayy and its only ben my 2 nd time so what im sayn is go see a councellor it will make u fell better and its also no one else has to no thy dont tell teachers or ring up parents or anything under ur permission i asked if my councillor cud ask my mum to come in and talk 2 does your mum know does she care 3 what names does she call u

stick and stones can break my back but not words( i don’t know if i said it correct) just ignore her.. i have siblings that make me cry..

drowned her out with music