Hello
You are only having fever ( mild degree ) and fatigue .
Tested for HIV on various occasion 3rd month, 6th months, 20th months and all tests are NEGATIVE but still you are having fever and fatigue.
I would like to say one thing that mild degree of fever with fatigue and loss of weight ( only 2 kg ) is not an indication of HIV ( particularly when HIV tests are NEGATIVE).
HIV infected patients have , fever,
pharyngitis,
lymphadenopathy, headache/retroorbital pain, anorexia /
weight loss, nausea/vomiting/diarrhea.
Mucocutaneous ulceration.
Cough .
Most of these symptoms , you are not having.
In my opinion your symptoms may be due to these reasons , these include:
1 Tension ( post sex )
2 Anemia , get in hemoglobin examination.
3 Deficiency of calcium is one most important cause .
4
Typhoid fever , get in serology test for confirmation.
In my opinion first of stop worrying and
consult a psychiatrist and get his opinion.
Good luck.