You have cervical lymphadenitis
with fever and weakness.
The most likely diagnosis may Tuberculosis
of the lymph nodes.
Do a FNAC to rule out Tuberculosis.
Do a chest X ray
for any focus.
Repeat the HIV test
after 1 month.
Any infection on the ear and oral cavity should be ruled out.
If the lymph node is hard or rubbery in consistency than malignancy may also be the cause and has to be ruled out.