I am incredibly bloated and nauseous and feel a squeezing sensation in my left shoulder blade. could this be cardiac related?

Splenic flexure synd: For 20yo female cardiac problem less likely. You may have gas in the spenic flexure. Your spleen is in the upper left portion of your abdomen, and a build up of gas in that region can cause left shoulder pain. The gas would be related to something you are eating. Diet candies have non-sugar sweeteners that can cause pain. Other food can be gaseous such as broccoli.