Welcome to HCM.
Those drugs were given to prevent allergy
and to treat the swollen tissues inside your nose. Donot come to conclusions unless proven otherwise.
I suggest you to review with your surgeon to find out the status inside the nose to rule out any secondary bacterial /fungal infection
causing the discharge, and ophthalmic opinion if he suspects a Dacryocystitis
Meantime stop using the spray, avoid blowing your nose and consult at the earliest.
Don't confuse yourself with brain tumours unless it is examined and proved.