What Causes Pain In The Breast Bone?

I started having pain right below my breast bone. stabbing going through my back, now the pain feeling like someone punched me in the stomach. I can not lay on stomach it hurts. I went to er and they gave me meds which helped for a while, GI cocktail did not help they did ultrasound and said it was not gallbladder, my pcp is ordering a test for gallbladder? I am at home still in pain and no answers?