Hello,
Chronic nausea can be due to stomach disorders such as
gastroenteritis, liver/gall bladder disease, cancer, medications, inner ear diseases like labrynthitis, ulcers/gastritis, metabolic like diabetes, hypothyroidism and adrenal diseases or neurological causes.
Take an OTC lactobacillus preparation and yoghurt with your meals. Drink plenty of fluids and eat small nutritious meals at frequent intervals instead of a heavy single meal.