Sorry. The new football stadium will be nothing more than a physical asset of the university like the library or science building. Since the marching band, flag corps, commencement ceremonies, and female football fans will use the facility, it is not considered "men's only". If the school decided to dig up the track for a new engineering school instead of a stadium, you would still have no Title IX claim.
The spirit of Title IX is that women are guaranteed equal access to opportunities at institutions receiving government dollars. Equal access to athletic opportunities, academic opportunities, scholarships, and the like. It does not mean that you get to save a track because football gets a new place to play. If they yanked your funding to pay for the stadium, you have a case. While a shame, splitting hairs about what the track represents will do no good. Plus, since the school made arrangements for the teams to use a high school facility nearby, they insured your "access to opportunity".