You certainly can. If you are drinking a diet soda or one with an artificial sweetener, all it takes is an initial exposure. Your immune system marks it as a danger to the body, like a pathogenic organism. Henceforth, you will react to it, or your immune system will attack it like a foreign invader. If this is the case, many artificial sweeteners and such are used in other products, so it may be prudent to consult an allergist and precisely identify their offending agent. They will begin a process of desensitizing your body to it. I'm sorry you had this issue; that is a bummer. Drinking some cola or the like causes you problems. That would be an annoyance, and I practically live off the sugar in regular Coca-Cola now. Your body needs sugar to perform the citric acid cycle, so you must get the energy in some way.