Need an advice about what to do

Hello everyone,
I just recently joined this forum mainly because i need an advice from you people.So here is my story.
Im a 14 year old girl who is about to go to high school from the next year.Im very shy and quiet person and i always care about my grades and try to give the best of me to do good in school.I've been bullied before not so long like an year ago from a guy that was in my class.He bullied almost everyone for no reason.I cant really say that he was bullying me because he was just saying inappropriate words to me and i never took that seriously.Few months later he left the school and went to another school (thanks god).After he left it felt like heaven.But recently these past few months a few of my classmates started bullying me again.I never did harm to anyone or said anything to provoke someone but they just started bullying me for no reason.I believe the reason was because they were jealous of me,of how i nicely dress up,have money etc.I never showed off to someone about my money because im not that kind of a person and my parents thaught me to be a good person.My classmates started acting weird and basically they started being rude to me every day.Today was extreme though.We had biology and the teacher had to do something so he exited the classroom.Then everyone started doing whatever they want.In the classroom there were beans in a box because the little ones were using them for a project.Suddenly i got bombarded with beans by my classmates.Everyone was throwing beans,pens and other things at me.They were also throwing water at me.My hair was full of beans as well as my clothes and bag.My jacket was wet.I didnt know what to do at that moment so i sat down on the chair and tried to ignore them but thry continued throwing things.I had no other choice but to sit and do nothing because they were going to beat me if i exited the classroom.I felt so much pain at that moment i felt like crying and ending my life.Im normally a very strong person but this got me emotionally really bad.When the bell rang everyone jumped and ran and i was left alone.I slowly packed myself and went home.I told my parents about it and they said they are going to talk with those that started throwing things at me.I think this will be useless because my dad was at school a lot of times talking to the bullies but nothing changed.I know that when my dad will leave they will start to bully me again and it will get worse.What should i do tomorrow? Please any advice is kindly appericiated.Also im not english so sorry if my english isnt that good i just tried.
Thank you!
Also i have helped a lot of my classmates in the past.Some of them had to deal with their parents getting divorced others had to deal with not having enough money for food and i helped every single one of them.It hurts to see that you have helped all of them and now they are bullying you with no right.I've never met that much ungrateful people in my life.I have almost 1month till summer break so ill have to deal with them somehow and after that i will never have to see them again ever.