I would like to add that you should start using your analog watch to keep track of time instead of the little e-clock on the app. The app should be used only for the directions, 5 minute warning, and distractions.
Whats the difference? Is it louder? More distractions? Whatever it is I would just keep doing it there if thats where you are doing poorly. Just seems psychological but it could be a bunch of things.
You might check Airbnb as well, if cost is an issue. But really, it might be nice to be in a hotel the night before the test ... Distractions etc at home eliminated, and the whole thing might be more of a fun adventure that way!