I would cut out the pressure and expectation of getting straight A's and add any extra curricular activities gradually, one at a time as I saw how the course load was and how I was feeling. Taking on too much, the bipolar might try to fight back, I would look around and talk to other students and see what courses they are taking and how they are doing and not overdo it relative to them; you don't have to "prove" anything, you have to work to be a healthy, balanced person.