I know you would have maybe liked a bit more sympathy and agreement but as someone who also experiences test anxiety (but not GAD) I will just offer some suggestions as to what helps me.
1. Don't drink coffee or other sources of caffeine before an exam. This can make the anxiety worse.
2. Eat a small high protein meal beforehand so your carb levels don't spike (anxiety) then crash.
3. Deep breathe and focus. I was taking a standardized test one time, and anxiety was getting he best of me but I recognized it...it stopped taking the test for a few minutes and forced myself to center. When you recognize it too which is important to be able to do, close your eyes and concentrate on your breathing. There are lots of techniques you can read like some say to squeeze/tense then relax each muscle in your body one by one. But anyway I went back to my exam and when I reviewed my score I had an A...the first 7 questions in a row were wrong, that I had done before I centered myself.
So no I don't think you have a case to appeal but you do have a chance to do better and pass nursing school