help me out

Dear RD,
I am 16. My best friend ditched me last month by talking bad things about me to some other person. I loved and trusted her very much but now I don’t know what to do. I thought that friendship is all about forgiveness. I made up my mind and talked to her about it. We talked and I thought everything was settled. But it wasn’t. She never called me like earlier or talked to me like she used to. It was her fault, she accepted, but now there was no sign of repentance. She got a new friend about whom she always bitched to me. She ignores me as if I am wrong. I feel hurt to see her like that. I was very true to her and never thought bad for her. I supported her even when she was wrong. Because of her I lost my many great friends but I never complained.
I sometimes think that I should go to her but every time it’s always me who goes to her. She never even bothers to come to me first. Now I have started feeling that by going to her I spoil my self-respect. But I am alone left in parties and other places.
I don’t know what to do. Please help me.