i can undersatnd your helplessness and anxiety
I would suggest you to get afresh set of investigations done without informing your docs.
and clot culture
5. Ig Mand IgG titers for dengue
6. urine examination
7. stool examination
8. Peripheral bood smear during the febrile episode.
9. chest x ray
Once the reports are available I am sure the doctor will be able to diagnose the cause of your fever.