Feeling nauseous? and the thought of food is disgusting her. she recently threw up a week ago from nauseousness and ever since then she still feels it

Nausea: Nausea can have many possible causes, with pregnancy at the top of the list. Good idea to do a pregnancy test if person in question is female and has had sex.

Find symptom's cause: Nausea/vomiting may be gi-related (food poisoning, peptic disease, gastroparesis, due to biliary & pancreatic disease, gas/bloat syndrome, small bowel problems). Consider "central" causes: motion sickness, vertigo, migraine headache, brain problems (some very serious). Also, rule out infection (? Urinary tract), medication side effects, pregnancy, even reaction to stress. Find & treat cause.