Help! I'm doing a public speech about a psychology report on Tuesday?

It consists of an introduction, a methodology, a results and conclusion section, I'm only doing the introduction section/ Three other people I worked with are discussing the other parts. It is a study on children with autism and we are discussing it for 45 minutes infront of teachers from different learning disability school. I hate doing speeches and I usually start shaking, blush and develope temporary face twitches which are suttle and go after I have finished speaking but it's still humiliating. Can anyone offer me any tips..either on how to do the introduction part of the presentation or on how to calm my nerves?