Quick relief for allergies

Patient: Hey! I’m going to an outdoor concert in five days, but the other day, my allergies started up… first a sore throat, and then a stuffed up, itchy nose. My usual nasal spray (with oxymetazoline) isn’t working as well as it used to. and the typical Clariting, Benadryl, etc. have never worked well for me… Any tips?

Symptoms: Stuffy and itchy nose, coughing (but not the main problem).