The jittery butterfly-like feeling that you are describing is a common complaint. It is caused by a change in your autonomic nervous system that results in activation of your stomach causing it to move. This can cause nausea and an uncomfortable feeling. Carbonated beverages are unlikely to help for this and thus, I would not recommend them. Carbonated beverages have carbon dioxide dissolved in them. Carbon dioxide is a very acidic substance and can be irritating not soothing to the stomach. In addition, most carbonated beverages contain a lot of sugar in them which is not health. The diet beverages don't have this, but do have artificial sugars which can irritate the digestive system.
I suggest that you schedule an appointment with your primary care physician
. He or she can listen to a description of your symptoms and perform a thorough physical exam. Your doctor
will want to make sure that nothing more serious is going on with your abdomen. You can bring up the question of carbonated beverages with your doctor, though I doubt he or she will think that is an acceptable therapy. Your doctor will be able to make a recommendation with your own person past medical history in mind. Good luck.