You seem to be suffering from a viral infection.
you need to take adequate rest .
Increase the intake of fluids and especially water.
As far as the white patch
over the tongue is concerned, it can be due to a fungal infection
of the tongue which is candidiasis
Such an infection can come up during episodes of illness or due to intake of antibiotics.
You might need treatment with both oral and topical antifungals.
Dr Geetika Paul