Fever for 20days. What should i do?

My father has long time type 2 diabetes, but uncontrolled. He took covishield vaccine on 13th April 2021, and started having fever since 16th April, it got worse and got fever of 102F and consulted doctors, they thought of covid and gave medicine, but 4days later it again came, he gave antibiotics 4days, after that it again came. Did blood test,(30th April-1st May) wbc- 11900, Hb%- 14.9 ESR- 48mm/hr, rest all normal, Sugar- 315, CRP- 43, ferritin- 387.9 HbA1c- 13.5(too high) Now blood test (5th May) Wbc- 6900 Hb%- 13.8 ESR- 64mm/hr(increased significantly) PPBS- 152( Reduced after having glynamic M1 &M2 for 2.5sdays) D dimer- 0.29 His urine test came normal,he is taking finevox cv 625 antibiotics+ paracetamol 3times a day,+ sugar controlling meds but still at night at least once fever is coming low grade(100-100.8 oral). No other symptoms,no pain in abdomen,no breathing issue,no cough no sneezing nothing only fever once a day(after 8 Really getting tensed. What should I do?