What happened to us?

Ok so i had this bestfriend, we clicked just like that on our first day at Burnside high but then after hning out with her everyday at school and on the weekends i started to loose my BEST FRIEND Tina. Things were getting really bad, my bestfriend started hating on this new friend and then i got an amazing bf who i love to bits. And he met this girl and well shes just so full of life it started to become unbearable. And only just lastyear i noticed something horrible about my new friend. All she'd do is say terrible things about the people i knew and were frineds with. My other friends had noticed it and decided they wouldn't be friends with her but in some way i felt like i couldn't not be friends with her. Shes beautiful but she uses it to an advantage which it shouldn't be used for. So after a holiday og thinking, i confronted her. It was so hard because at the time i didn't want to loose her as a friend but i also couldn't stand the way she talked about people behind their backs. So i sent her a text telling her i couldn't be friends with her anymore. I know i should have done it in person but it would have been way to hard for me. Im a shy person and im not very good at sharing my feelings with people so i just loc them up in my head and heart and let it overflow. So she text back saying why and i answered but it came out so bluntly and it sounded really bad and just a few days ago i recieved 3 msgs from a boy i know. They said some really nasty things which made me cry so much. I honestly wanted to hurt myself although i was to afraid to. But the weird thing is the boy used to be my best guy mate until he met this girl and she just completely took him away from me.I felt so empty and ashamed of what i had done that i didn't talk to anyone for like a week. Then one day i just couln't bare it that i blurted everything out to my mum who was very understanding about it and offered for me to move schools which i was kinda pleased about. But i have to stay at the same school to start off with because its a very important year for e as im starting NCEA so i have to see how it goes and if it gets to hard to handle im allowd to change schools.
So yeah every now and then i get a rush of sadness through my veins and it just makes me want to cry.