I’d recommend drinking water too. If there’s nothing else open, drink a load of water and go to bed. At least you’ll wake up bright and early for when the store opens.
Does your dorm have a kitchen, and can you get in? A teaspoonful of baking soda (NOT baking powder) in a glass of water will help a lot; otherwise, water will help, but not as much.
As was mentioned, BAKING SODA is a capital remedy for sour stomach. One teaspoon in about 4 oz of water works fine, but I recommend substituting carbonated H20 or mineral water. In my experience, Calistoga water is superb. The fizziness precisely duplicates the effect of Brioschi, an OTC remedy that is, alas, difficult to find in many locales…
The relief is INSTANT. The downside is sodium overload, which may be of concern to those who must restict their intake of sodium.