I was in your position BBCC. I dropped one of my C grades (Maths) and got A*AB, A* in Economics, A in Computing, B in Graphics. It is definitely possible. I tried to keep my exams to a minimum - I only sat 4 this year. I retook Computing unit 1 which was my weakest module and sat Computing unit 3, Economics 3 and 4. With such few exams and generous gaps between each I was able to maximize my time focused on each exam and thus scored higher this year. Good luck, I can tell you being in your situation that it is possible. You have to work your ass off this year, but with University as a motivator you'll be much more self disciplined than you were last year. Good luck!