your symptoms that you have mentioned lead to a diagnosis of viral with a superimposed bacterial picture, because you have taken antibiotics with some improvement. the other reason could be the antibiotics that you have taken you could have become resistant to them hence they are not clearing the infection you have
i would do a blood test
to rule out and confirm whether viral or bacterial
it cant be malaria as you dont have joint pains
with vomiting and diarrhoea and you have to travel to an endemic area of malaria to get it.
it cant be typhoid as you get bloody diarrhoea with fatigue.
it cant be gastroenteritis
as you will be vomiting and have diarrhoea with dehydration
it cant be viral bronchitis
because this infection is way down in your lungs while yours is just in upper throat.
would suggest get your throat checked and chest checked by the doctor and prescribe the medications accordingly.
get well soon and takecare.