I've managed to calm down. It amazes even me. Sometime Friday evening, I managed to hit some sort of a stride with doing my presentation. I finally realized how I wanted to organize it, and once I was sure about that, it was just a matter of setting out to get it done. It was due on Thursday, and I'm still not done. But I'm confident I will have it finished for submission tomorrow - Sunday. It's such a relief to have stopped freaking out. However, give me a day or two after turning it in, and I'll probably start freaking out about the actual having to present it.