Om Sai Ram,
The things happenening between u and your friend r not like true friendship. Indeed u bbelieved and trust her, but she don't. Means the friendship was from your side and she was just using u. Now the question is what to do. Better way is to maintain distance from her and that too not at once but slowly. if she behave with u wrongly, you should not do the same. What all ishappening with her is due to her conduct/jealousy. Therefore, why u mov forward on her path.
For you it is adivsable to not to change your conduct and always be polite to others.
Jo Jisase Jaisa Behaviour karta hai use uska vaisa hi anubhav hota hai.
Hamara karma hamer sath hota hai wahi hame achchha bura fal deta hai.