It is likely that you are suffering from chronic rhinosinusitis
with post nasal drip
(i.e., the mucus buidup in your throat) that causes cough at most times and a continuous sensation of 'needing to clear' the throat.
Allergy testing must be done to exclude aeroallergen sensitivity such as house dust mite, mold allergens, animal dander etc by skin prick or specific IgE blood test
Gastroesophageal reflux disease
does not help with the allergies, causing more throat problems and heart burn.
You definitely need an upper GI endoscopy if this is going on for some time.
Please STOP smoking if you do.
Chest X Ray, paransal sinus CT will be helpful in knowing the extent of disease.
Long acting antihistamines and nasal sprays are required for long duration than only a few weeks.
If the allergens are found and the rest of the investigations are normal, oral or s/c immunotherapy
will help and that is the long term solution.