theotherguy, nobody can tell you what to do. All we can do is tell you what usually happens when you're in different situations. If a girl is interested in you as a friend, it rarely works out in other ways simply because she's more comfortable that way and also because she doesn't see you as bf material (for reasons mentioned above).
Should you tell her that you had feelings for her? Why? You think that will change anything? Most times you can read what a woman thinks by just looking into her eyes and/or by paying close attention to her actions. Man up! There are plenty of girls out there so don't waste your time on this one.
-to be nobody but yourself in a world which is doing its best, night and day, to make you everybody else means to fight the hardest battle which any human being can fight; and never stop fighting.- e.e.cummings