I inhaled dust from a counting machine in the bank. Ever since then I ve been having chronic catarhh and weekness. Pls what medication will I take?

Irritant. Occupational lung disease can be a serious issue. It might simply be a mild case of inhalational irritation of the lung lining to hypersensitivity pneumonitis to infection to ? You really should get this evaluated by a doctor, and consider getting a chest x-ray to get a very basic picture of your lung tissue. Medication recommendations without a diagnosis is dangerous.
Occupational lung. You need to get a good exam -starting with your nose and lungs occupational asthma and other lung diseases can occur after inhaling various dusts. A cxr and pft are worthwhile.