Feel free to share with us as you are getting the work done, sarahblue. We will be happy to congratulate you.
"Get 'er done!" You can do it! Just start by writing down whatever comes to mind about the internship for as long as you can. That will be the beginning of a real rough draft. And then take the small steps. And as you say, you can start getting feedback from your advisor.
Hey, you wrote a novella, so in some ways, this project will be easier!
You are NOT a fake, ya hear?