in the same boat as yout but geography instead of psychology! honestly i am just trying to make the most of my free periods and revise for a couple hours after school. Making a plan of what topics you are going to focus on makes revision a lot more structured so i would suggest doing that. In all honesty its not the end of the world if you don't get the predicted grades you want, the real exam counts the most and you can take a gap year and reapply! Do the best you can in the time you have.