Different folks and ENT docs will tell you several things… Deviated septun, allergies, chronic sinusitis (inflammation of inner linings of nose), dry air, sleeping positions, etc
I have had this condition since over a decade and seen tens of ENT specialists with varying opinions, but really no one has a cure or an explanation. Most ENTs will recommend
- daily saline nasal rinses with alkalol,
- nasal sprays such as Nasonex or RhinoCort or
- even a day surgery using CoBlation technique.
However, despite people trying all of the above, no-one yet has been fully cured, its only been mild symptomatic relief at the best, if conditions didn’t get worse after surgery due to “dry nose syndrome”
First and foremost, don’t believe anyone who comfort you and blame the environment … dry air, allergies, etc. Yes those external factors may exasperate the already existing problem which is purely INTERNAL, but they are not the root cause. Others folks living in identical conditions don’t exhibit similar problems.
The cure lies in a lifestyle change and holistic medicine. That is the only way to calm the overexcited nerves. Inflammation of the nasal passages is a sign of exhaustion and excess heat which needs to be cooled down. Improved blood flow in the nasal passages can remove the excess heat. Blood thinners like Gingko Biloba extract may help a bit.
Also try to cut an onion into 2 halves and heat on a stove pan for 10 mins. Then when its reasonably warm to touch and not too hot, place the flat edges of the onions over the sinuses and forehead. Keep for 10-15 mins and repeat for 7 days.
Also lastly but most importantly, try to make a solution of ghee-camphor, which is clarified butter melted in a pan, added with few drops of edible camphor. Place a few drops in each nostril while head is hanging vertically downwards such that the solution reaches area between eyebrows and not the throat.
Also practice quietude with soft talking, no shouting, less talking, no sarcasm and no harsh words…
LifeStyle changes begin here 
Everything helps a little bit.
Good luck !