Constant nausea and vomiting

46 year old female, constant nausea and vomiting for 8 months. Pt. Has history of polycythemia Vera, cervical cancer ( total hysterectomy), thyroid cancer ( total thyroidectomy), hypertension. Pt. has been hospitalized multiple times over the last 8 months with no answers. Pt. has had multiple CT’s and X-rays of the stomach, as well as stomach emptying study, endoscopy, and many blood tests. Everything is “normal”. Doctors say she is an anomaly and cannot diagnose her. They have ruled out gasteroparesis, stool blockage, spreading of cancer, and food allergies. Pt. cannot keep fluids or food down, has very high and very low blood pressures, has had hallucinations, bloody noses, chest pain (usually with the vomiting), has lost 80lbs in the last 5 months, and has been in pre-renal failure many times due to the dehydration. I know there is plenty I am missing so please please please ask questions and I will answer them to the best or my ability. The Pt. is my mother who I am convinced will die unless i find someone who has seen this sort of thing can before and help find me answers. She cannot just be an anomaly with no answer’s. Someone out there has to have seen this before. Please help me.