Hi Dynames ,  First let me say her best friend did not get her to cheat on you . She CHOOSE to cheat on you , she is responsible for her own actions , no one else is , she is .   Then the bi-sexual issue came out of this and you forgave her . First she says you are drifting away from her , so you make an effort to make sure she knows you love her , then she calls you clingy and has now stopped telling you she loves you .  She is 17 years old and I don't think she knows what she wants . You do not trust her and you shouldn't . I am sorry to say this but yes she's found someone else .  You are 18 years old , got your whole life ahead of you .  I think you need to move on find a girl you can trust , one that loves , respects and values you .  This girl does not feel any of this for you .  You deserve better treatment than this .