Feeling Stressed with College Group Project and Internship

I've been feeling so stressed lately with college. Two months ago we had to sign up for a group project and my partner and I decided to complete it and present it Thursday to our instructor. However, the same instructor is requiring us to get an internship which we just learned about recently. I only got one employer that offered me an interview and it supposed to take place the same time as my presentation. I forgot about the presentation until tonight, so i said i would be available for the interview. I could do the presentation earlier, but only if my partner agrees. I fear that if I ask to reschedule the interview that I will look unprofessional. I don't know what to do and it's making me really anxious.