Do not listen to medical advise on a public forum. Most advice will not help and some may actually be harmful.
Ask a doctor or at least pharmacist.
My current understanding (as an engineer not a medical person) is that the human body shrinks one nose side itentionally. This way you have a wide nose way and a narrow one. This leads to different airspeed which lets you smell different stuff better. The body changes sides in intervals. One allergic reaction is that the interior of the nose swells more. So the narrow path will become even narrower until it blocks.
There are substances that combat this swelling, but using them for too long can severely damage your sense of smell and health.
How come most people try to solve the no heat problem instead of the food that does not need heating problem?
Some stuff that can taste well even "cold":
Canned tuna + precooked canned beans + onion + salt pepper oil vinegar.
Watermelon (quite inefficient when it comes to nutritiom but tasty)
Bread + mustard+ hard cheese or certain types of sausages (especially smoked with low amount of water inside).
Most vegetables and fruit will survive 5 days if they do not have defects and you can keep insects away from it.