Hello. I'm sorry you don't feel well. It isn't possible to diagnose your condition without an examination, but several thoughts come to mind:
A viral illness could account for your symptoms. There are a number of viral diseases that are associated with fever, headaches, body aches and right upper abdominal pain -- which could be a symptom of liver inflammation -- including infectious mononucleosis
("mono" or glandular fever
) and hepatitis A, B or C.
Certain bacterial or parasitic infections, such as Mycoplasma or amoebae, can cause liver inflammation, too. These infections typically trigger fevers and body aches, which we call "constitutional symptoms."
, such as that caused by inflammatory bowel disease
, lupus or rheumatoid arthritis
, can present with fever, right upper abdominal pain and constitutional symptoms, as well.
Finally, gallbladder disease is a classic cause of right upper abdominal pain, and it occasionally presents with a fever, especially if the bile ducts are obstructed (such as by a gallstone).
In any event, your symptoms are a bit worrisome, and I would suggest you see a doctor at your earliest convenience. Further investigation is warranted here.
I hope that helps, and good luck!