Barbara
                    
                    
                    
                    
                    
                    
                    
                        
                        
                        You should find another doctor.  It is unlikely you are dehydrated.  These are the signs of low blood sugar.  I suggest you go to an endocrinologist.  They study the body's metabolism and should be able to figure this out.  Try to go to a big medical center that is university affiliated.  The best doctors are there.