Your nausea may have little to do with the GI tract & therefore may not always respond to vomiting.
Biliary & pancreatic disease may be present. Gas/bloat syndrome? Consider "central" causes like: motion sickness, vertigo, migraineheadache, brain problems (some very serious). Also, rule out infection (? Urinary tract), food poisoning, medication side effects, pregnancy, & even stress. See doc.
Would you like to video or text chat with me?