Any headache associated with it? I'd get CBC, CMP, vitamin B1, B12, folate rbc, Iron Deficiency Panel, vitamin D 25-OH, A1C, urine pregnancy test , U/A, and see how that goes.
Hello~Sometimes anxiety and stress can be the cause of what you are experiencing. I suggest seeing your GP and having some gastric tests run as well as some blood work. Also, is there any chance you may be pregnant?
Nausea could be due to various underlying causes. How long has it been happening? When were you last healthy and eating normal? Any other symptoms? Any stomach aches or cramps, diarrhea, vomiting, fevers? Any sick contacts around you? If you re in the childbearing age and a female, you should take a pregnancy test as well.