You probably have checked at the hospital if you have an inflammation of the gastric mucosa? Have you tried Iberogast? No I‘m not recommending it because it’s irresponsible to recommend anything in a forum not being a doctor let alone just by reading a post with symptoms.
A colleague of mine suffered with weeks of nausea and throwing up, she was taking AD, a doctor thought this could be a side affect. After a strict diet things calmed down.
Get well soon!