So, I told my best friend that I love her, but what does THIS mean?

[Mimi]

I don't think she's totally against being with you as more than a friend especially with that line "Although I'm not sure if...", she's probably confused and needs time to think. She wants to keep you near but she's worried that if she rules you out as a lover that she'll also lose you as a friend. So please don't threaten her with that (Though you don't seem like the kinda person who would).

Just give her time. You both still want to have each other near, and while telling her your feelings jeopardizes your friendship so does having a relationship as more than friends since few relationships end with being able to stay friends. I think you also have to think in the long run if the friendship means more to you or a relationship with her.

Best of luck