itchy nostril, constant sneezing

Welcome to the forum, nothappy.

So sorry you are having such misery. I have no idea what your problem could be. I've had no experience in this. We're just patients here, so we can't diagnose anyway.

I'm glad you are seeing an allergist. Hopefully he's a good one and will figure out what's going on. I suggest you get a copy of your records from the ENT to take with you. No use doing the same tests over again.

I tried acupuncture for something else and it was less than helpful. It hurt a lot, so much I had to insist some of the needles be taken out.

I'm not fond of neti pot because it only works by gravity. Personally I like the larger type squeeze bottles to wash with more pressure.

You might try keeping a journal to help with diagnosis, maybe find the "rhyme or reason." I keep a food journal with date, time, medicines, all foods and drinks. I put in any symptoms, headaches, upset stomach ... My allergist got me doing this for food intolerances, but it could be helpful for lots of conditions - seeing what happened just before the symptoms started. People with migraine headaches have to look back as far as a couple of days to find their triggers (often sulfites).

It's possible your sinuses are just draining. Mine often decide to let loose after my morning coffee warms and liquifies thick mucus. That's when I use the sinus wash. The maxillary sinuses drain upward, so if you lie down or bend over you can get a gush.

There are many types of antihistamines. You might write down all the brands and generic names you have tried and the side effects. It will help the allergist. I carry around a 3 page list of all meds, including generics. I have tried and side effects and the good effects too. I can't remember all the names. It's often helpful when a doctor wants to prescribe something I've already taken.

Best wishes!