Yes. It is possible to spread diseases through an infected tongue depressor.
Diseases transmitted by tongue depressor are like
Mononucleosis, Respiratory viruses, including influenza and coronaviruses, are present in saliva and respiratory droplets, Herpes Simplex Virus (HSV-1) causes cold sores, this virus is highly transmissible through direct contact with saliva or an active sore, Cytomegalovirus (CMV) poses risks particularly to
pregnant women and immunocompromised individuals, Streptococcal Infections and common cavities and gum disease are driven by bacteria (such as Streptococcus mutans).
Next Steps
Be careful of doctors. Doctors can kill as witnessed in some hospitals. Treat yourself online via Google, youtube, or Practo.