Em i losing my best friend???

[Vanny]

I went out with my best friend.. which is a girl.. and i'm a girl.. it didnt work out..she had a really huge crush on this one chick before she went out with me.. but we both came out saying our feelings towards eachother.. she said she wanted to go out with me all along but since i was going out with this one guy she didnt plan on telling me how she felt.. anyways we went out.. so then we broke up.. its been like 2 months since we broke up and now the chick that she had a crush on is interested in her.. so they're happy... so tell me why i feel like crap??? i love her so much still.. but the other chick could offer so much more than i can..so tell me why i feel like i'm getting my best friend taken away.. she hangs out with her all the time now.. it hurts soo bad.. i have to act like i'm happy for her.. while inside i feel like i'm dying.. what should i do? i already talked to her.. and she thinks i'm totally fine with it.. i still love her so much.. but its too late now.. help me??..