You should immediately get a psychiatrist to write a note to your school's disabilities office so that you can get special accommodations - I do not know what they would be in your case, but the doctor and the disabilities office should come up with something. Maybe written assignments in place of presentations while you are working on getting the skills necessary to present without crying.

If I understand your situation correctly, your biggest problem with school is not bipolar but anxiety. With limited success, medication and therapy (therapy includes doing things that you are afraid of doing) are effective. There is a forum here for anxiety, panic and phobias - you may want to post there about your failures with presentations and such. It's an anxiety issue more than a bp issue, and anxiety is at times so strong that bp people carry a separate dx of anxiety, even though the more basic, garden-variety anxiety is present in many bp patients without a separate dx.