There is no absolute need to drink gingerale when you're sick. It's mainly good for an upset stomach. What you described sounds more like a sinus infection, an upper respiratory tract infection, or something along those lines. As in, you probably don't need the gingerale.
But even if you do have an upset stomach, it isn't the carbon dioxide that's helping - ginger itself does that. So, a small amount of ginger added to food/drink will help.
Of course, keeping hydrated is important. Things like clear broth, or dilute Gatorade are good. The reason you want to dilute things like Gatorade is that the really high sugar content itself can upset your stomach. If you're feeling really sensitive, you might try drinking only room temperature fluids (really cold stuff can cause upset).
If you're feeling really sick, or your symptoms persist, see a doctor. Continuing with the nausea train of thought, a prescription for Tigan will greatly help that.