Hi,
Thanks for posting your query.
With the available described symptoms, there appears to be possibility of Acute viral upper respiratory tract infection with secondary bacterial infection and possibly persistent source of infection.
You should consult with internal medicine specialist and ENT surgeon simultaneously and should go for thorough check up.
You should go for complete blood count, erythrocyte sedimentation rate (ESR) and chest x ray.
You should take complete antibiotics therapy, mucolytics and decongestants.
You should avoid cold drinks, oily food and yogurt.
Perform gargles three times in day; a glass of lukewarm water with a pinch of salt.
Take care,
Dr. Mayank Bhargava

Hello,
Thanks for coming to HCM. Mucus production in small amount is a normal protective & moistening phenomena which keeps getting cleared constantly by cilia which are hairy structures on mucus membrane. You have mentioned that you are a teacher, which requires use of voice for long hours continuously or intermittent; this can be one cause due to constant . Other possibilities include viral upper respiratory infection, sinusitis with a post-nasal drip/draining, some milk products (yogurt, cottage cheese, butter), allergies (you need to be evaluated to rule out this since you have exposure to pet, forest/plants, ?some food allergy), deviated nasal septum, and any small growth in that area.
You should visit ENT specialist and get your self evaluated. Meanwhile, you should drink more fluids and do hot water gargles.
Wish you get better soon!