I took a drink of diet soda this morning and got kind of a burning feeling in my chest (intense chest pain ). Since then, I have had pain in my chest all day, especially when I take a really deep breath. I know that drinking a soda can cause pain (too fast down the throat , I ve felt that before) but this felt different and the pain has been lasting (though it is not nearly as sharp as the initial incident). Medical background: 28 years old, female, acid reflux ( GERD ) for 3+ years on medication (omeprizole) for 1 year; I also take cymbalta.