I miss my ex best friend?

It's been four months since I've spoken to her and the reason that we stopped being friends is because she had a best friend before I came along and that best friend got envious of the growing friendship between me and my ex best friend. Anyway, the girl talked about me all the time and my ex bff never stood up for me so finally one day I asked the girl to stop talking about me but then she turned around and told my ex bff a bunch of lies and now we all don't speak. I miss her a lot but since it's been like 4 months, I'm afraid it's too late.