Hi..
Welcome to HEALTHCARE MAGIC..
I have gone through your query and can understand your concerns.
As per your complain nasal discharge with pain and redness can be due to 
allergic reaction causing 
Allergic rhinitis while can be due to 
sinus infection etc..
Foul smell or ammonia like smell can also be due to sinus infection, foreign body inside nose, nasal [staph] infection etc..
I would suggest you to consult an Otolaryngologist and get evaluated and a thorough clinical evaluation can help in diagnosis and can also do a nasal endoscopy and MRI of sinuses to rule out the exact cause of problem and treat you accordingly..
In case of infection he can advise you to take antibiotics like Levofloxacin or Cephalexin, anti-inflammatory painkiller like Ibuprofen, decongestant like Pseudoephadrine, anti allergics like Allegra or benadryl, saline 
nasal irrigation, steam inhalation and use a humidifier in your room..
Decongestant nasal sprays containing 
Xylometazoline can help..
Hope this information helps..
Thanks and regards.
Dr.Honey Nandwani Arora.