I am being cyberbullied by a person at my old school, what do i do?

[Lollipop]

So tomorrow is the first day of my new school and i just got a text on my iphone from a unknown person and they said "you better stop bullying my bff or im gonna kill you" And i was like "what?" Well there is this really fat kid from my old school and he was so mean, he hacked into my account with his stupid "group" and sent texts to all my contacts that were extremely mean, then he like ganged up on me and turned into a goody by "telling everyone" in the school that i was a cyber bully and even telling the principal about it and showed pics of the texts he sent on my account. That happened like 2 months ago and i already said sorry for what i didnt do and now on the night before my new school i get over 50 texts from different ppl threatening to beat me up and stuff! What did i even do? I blocked the "friends" but more came. I told my parents but they can't do anything as i moved school and have no contact with the old students! What do i do? Last year the comments were so harsh i wanted to cry and i stayed home for 2 days to stop embarrasment. Help please, i cant take it anymore! I thought this fight was over! I am 13 Btw! And on halloween last year they threw eggs at my old house, i saw them with my own eyes! I just wanna cry myself to death! Please help i want to start fresh at my new school and leave bullies behind! I cant stop the messages!