What should I do with her?

I have a friend that I grew up with and am really close to. We have known each other a LONG time. Our friends kept telling us that we were special since we have been together for so long and that we should be together. Well, I finally mentioned it to her and she told me that she loved me. She said that she has loves so much and has for a long time. She also said that she refuses to lose me by getting involved. I asked her if she loved anyone more than me and she said no. I keep thinking about her and we talk and hang out all of the time. I am afraid, though, that if we don't act on it, that we might lose each other forever.