High school (update)

I've been faced with alot of pettiness from the girls at my school and of course I've unfortunately been caught up in it. I have lost alot of friends because of this and have been left confused (because they were my friends). I don't want to focus on it too much as I'm doing my gcse's and I need to work hard, yet I can't help but feel sad and alone(this is becoming a distraction), I can't help but cry all the time, I feel uncomfortable going to school with knowing that people are speaking behind my back and knowing private stuff about me. And I just feel depressed... And I don't know what to do anymore, any advice? UPDATE: The girls added me to a whatsapp group chat to have a go at me, I tried to make amends and be the bigger person, then they left... I feel even more worse than I did before, but the best part is that I'll work even more harder in school.