Its sounds like you are worrying yourself into acid reflux, I had the same problem before exam week when I was in school as well. It may help you if you took a B-50 Complex Vitamin for stress. These vitamins help your body fight the physical symptoms of stress, and could help you get rid of anxiety induced Adid Reflux.
It worked for me when I was in school, I took Stress Tabs, (B50 Complex) for about 3 weeks before exam week and I never had a problem with acid reflux again.