End-of-internship presentation coming up and I am scared af!!

End-of-internship presentation coming up and I am scared af!! One of the most important presentations of my life is coming up. This is one of the determining factor as to whether I get a job or not. I honestly do not have the mental energy to go through interview prep all over again, so I really need to get a return offer from the firm I am interning at. Overall, I have done pretty well so far. Now it is down to the final boss, the PRESENTATION, and it is seriously consuming my mind. Any suggestions on how I should approach it? And maybe some motivation? I just want to feel mentally ready. Really appreciate your comments!!