For 1-2 yrs i get severe nausea nightly, recently tested for some stomach parasite but it was negative. not pregnant and it happens even if i dont eat?

See GI doc: Nausea often comes from gut problems with slowing of motility, but may have other causes as well. Timing suggests this could be a drop of blood sugar, or a fatigue issu, or constipation. A full work up is needed. You can try over the counter meds like Bonine for travel sickness, or probiotics to reset gut bacteria. Keep looking for the answer.

See GI: Need to consult a GI specialist to find out the reason. Sometimes the problem may be neurologic and a neurologist consult may be required after GI problem has been ruled out. Reflux can also cause nausea in some people.