Just an idea
Just a thought - before you use cortisone to clear your nose, I suggest you try the natural "Pseudoephedrine" (not Ephedrine!). Works great for me in terms of clearing my nose and mitigating some slightly asthmatic symptoms. Just be VERY careful with the dosage, especially if you have high blood pressure, heart conditions etc. This stuff is also found in many anti-cold syrups. However I can't vouch that it's permitted in commercial aviation. Also in some countries this stuff is available OTC in the pharmacy (e.g. Germany) and in others considered a narcotic (e.g. UAE) with all consequences involved.
Hope you get well soon.