What Could Be Causing Cheesy Pus Smell in Nostril After Rhinoplasty?

Sounds like you have may have an infection, or at least have become colonized with bacteria that don't smell so nice.  Has anyone cultured it?  It may be prudent to have your surgeon take an intranasal culture of the odd smelling discharge.  This will at least direct the appropriate antibiotic treatment.  

Abnormal smells following rhinoplasty surgery can be caused by a variety of problems. When these smells are encountered six weeks after surgery they should be aggressively investigated. It’s therefore important to see your surgeon as soon as possible.
                The smell that you describe could be related to a large number of potential problems. These may include nasal or sinus infections, would healing problems, necrotic tissue, crusting with retained mucous secretions, and retained nasal packing.

                In the majority of cases nasal cleansing with saline irrigation will solve the problem. In some cases antibiotics may be helpful as well. 

A bad odour can be a sign of infection, therefore you should see your surgeon again for another diagnosis.