Struggling to Get a Diagnosis for Chronic Nausea and Vomiting

I am struggling to get a diagnosis for chronic nausea and vomiting- It began almost immediately after my brother unexpectedly passed away. I have had an upper endoscopy, blood tests, etc, and have been told everything looks normal. They are saying right now it might be conversion syndrom/functional neurological disorder. I also experience chronic pain and fatigue, but those symptoms have been longer lasting. Is there anyone here who has had a similar experience? Is there a specific medication that had proven helpful? Right now I take Ondansetron as needed.