What's the real, root problem here? Procrastination? Nerves? Not knowing the information? Other circumstances? You've come this far so you're obviously capable. If you don't put in maximum effort now you'll have nothing to show for it all. Take deep breaths, calm down, and work out what you need to do to give it your best shot. Everyone feels like this at some point - you're almost there, just a little bit further to go. Good luck!