Multiple Tumors both sides of upper abdomin(abdomen)

I have tumors on both sides of my upper abdomin (abdomen).  I cannot stand more then five minutes as the pain gets so severe I have to sit down to relieve most of the pain.  I am constantly in pain and when I eat it gets worse and the nausa gets out of hand.  Can you give me an idea of what you think it is.  The tumors on the right hand side hurt worse then the left side.  This is effecting my life and I am very nervous about seeing a specialist.  Would this fall under Gastro anyway?  Your reply would be helpful.