Thanks for the query to H.C.M. Forum.
It seems you are having drug fever
or infectious fever.
The main point indicating towards serious infection are ,
1 Elevated level of E S R (sedimentation rate)
2 C reactive protein
( crp) .
However disease till not diagnosed, it is very sad.
In y opinion when such type of situation occurs , get in blood for culture and drug sensitivity test and start treatment .
In my opinion consult primary care
physician and get his opinion ( one more opinion).
However in this type of disease I used lemon juice twice in a days with lukewarm water for 3-6 months on empty stomach.