Hi, Welcome to Health care magic forum.
                 As you describe, it is difficult to diagnose from your description. Left abdomen is a vast area of the stomach. 
                 The possibilities are the gastric irritation, spleen or 
pancreas or 
kidney pain if pain is present in the upper part.  It may be be the pain of the left 
ureter with infection, or stone, or descending colon, if in the lower part, may be of 
urinary tract infection of bladder, or stone in the lower part of ureter or rectal pain.  
                  I advise you to consult a surgeon for diagnosis.  
                  i usually prescribe to my patient with such symptoms 
omeprazole, 
domperidone, and 
antacid gel, till the diagnosis is established.   
                 wishing for a quick and complete recovery. Thank you.