Oh dear. That situation sounds awful. It sounds like your nerves got to you. Your going to go back in there with a level head and your going to excel! My RN clinicals weren't as tough as my LPN ones. What I did for tough instructors was imagine they were naked or something. It made me smile......a lot.
If humor doesn't work, start working on your stress management skills now. A big part of clinicals is not just the knowledge aspects but also to strengthen the fortitude of that student. BREATHE! I practice mindful breathing a lot. Breathe in slowly 1-2-3-4-5, out 1-2-3-4-5 that's 1. Do that till 10. Only thing that your mind should be focused on is those numbers. BREATHE!
And here's a hug. Do come back and share with us how you doing. Get your RN girl!