I was really nervous about my speaking and listening, we had to do a court case and a speech about work experience, which was AWFUL =[. BUT the best thing to do is just practice your notes, and try and keep calm. I thought I had done awful as I am quite a shy person but I didn't. By the sound of the rest of your coursework grades you have a natural flair for English, good on you- it's only the best subject! ha ha.
Also a good thing to do is when other people finish their speech etc, is to ask them a question about something specific to their speech. For example, taking in a careers speech, the person at some point says '' I really enjoyed working at the primary school, but I want to do something more adventurous in my life'' , you could inquire about what their ideal career would be or why primary school isn't adventurous! SERIOUSLY the cheesier the better, they love that stuff. =]
Try and note down some quotes/points that the person brings up during their speech and then refer to them when asking your question.
Finally just try hard, I'm sure you will do great. Don't worry about stressing over it. I stress loads but I think it just shows you care and are committed.
Good Luck XD