Welcome to HCM forum and thank you for the query.
You are suffering from Chronic Rhinosinusitis
with underlying Allergic Rhinitis
i.e. you got an infection in your paranasal sinuses
. In most cases, it can't be cured. Therapy is needed to reduce the symptom and improve the quality of life.
You will be benefited if you do Nasal irrigation
with saline solutions or saline spray. Washing your nasal cavity with saline reduces postnasal drainage (that you complained "thick mucus in the throat"), removes secretions, and takes away allergens and irritants.
You should get your nose thoroughly examined by a ENT specialist
as there may have nasal polyp which needs special attention.
Intranasal steroid spray is very effective, but it should only be used with a doctor's advice. As you have constant runny nose, you can use OTC Anti-histamine drugs.
I think you have also decreased sense of smell !
Hope, this helps.