Hey hun,
first of all can I just say I'm sorry. No one deserves this. But am I surprised? No not the slightest, you wanna know why? This is typical high school behaviour. To be honest you remind me of myself, I was that girl that the popular group of girls decided they liked so they became friends with her, but not real friends because the second you said something they disagreed, they instantly dislike you and made you feel like ****, then they will forgive you but ONLY to do it all over again. It's toxic.
My advise is TO DISTANT YOURSELF. You said if you walked away you'll get taunted like a snake? Yeah and so what? Let them because they will get bored soon and if they keep doing it just look them deadpan in the eyes and say ''yeah and so what? okay.'' it'll just throw them off because they'll see that they are unable to phase you. Honey if you don't want to see them around at lunch and break time, head to the library, grab a book and sit down or go to the ict department and go on the computers. In class if you're worried because they are in the same class as they will bother you? they won't, only if you do not sit with them. Talk to the teacher maybe before class and ask to be seated on the other side of the room. Focus on your work because i hear GCSE's are real tough now. Real friends will come to you. You'll find them, don't stress about that right now, because they could be in the other classes and you just haven't had the chance to get to know them. Right now you need to focus on getting rid of those toxic girls, because WILL eventually leave you be..the rumours will then disappear too, people will forget.
AND MOST IMPORTANTLY BECAUSE I CAN'T STRESS THIS ENOUGH:
HIGH SCHOOL FRIENDS ARE PEOPLE YOU WILL NEVER SEE OR SPEAK TO AGAIN.
I'm in year 13 love, it's been a year and a few months since i've seen people from my high school (not counting close close friends). Give year the rest of yr10 and year 11 a chance to make some new friends and if you still hate your school, you can always apply to a new school for sixth form and meet some really new awesome people.