is it LPR? ENT suggesting since antihistamines not working

I got sick in early Feb with a very bad head cold or one of the new viruses running around. I stayed sick for over a month, had severe one-sided post nasal drip + mild ETD (ears felt funny and sloshy and noisy, mild off balance/dizziness sometimes) for 2 more weeks until I caved and got antibiotics, then a 1 week course of prednisone, to try to stem the post nasal drip. Two weeks after that, my PCP put me on Flonase (1 spray each nostril) once a day + saline neilmed rinse once a day, and that helped a lot.

Finally got in to see a sinus specialist ENT, who took me off of Flonase to get me on budesonide-infused neilmed saline rinse once a day + added azelastine spray (2x spray twice a day) + swapped me to Claritin because he was sure it was allergies. He was sure it was because he asked if I had any allergies (I do, tested for dust mites 8 years ago but all my reactions have been 100% dermal (hives), never respiratory). 3 weeks after that, my post nasal drip and ETD symptoms were considerably worse.

At my followup, he said he was going to send me off to get re-tested for allergies, then did another endoscopy (mind you, my PND was much worse at this point from being taken off Flonase), said he saw some traces of cobblestoning and irritation at the back of my throat and said maybe this is GERD/LPR and told me to take omeprazole 20g twice a day for 3 months. He also told me to do all the GERD stuff, but I already do it for general health and have for years -- not eating after 8pm, no big meals, elevated pillows, I don't even drink caffeine or soda or alcohol. I do, however, drink calcium-fortified Tropicana light orange juice 2x a day. I have never had a sore throat, hoarseness, or cough with this.

Could the ENT be right or is he just going through all the possibilities of what this could be? I asked him if this could be something like long-term post-viral inflammation and he was unsure, he wanted to try this first. I'm leery because I don't want to get rebound reflux from 3 months of omeprazole if I don't even have LPR to begin with.

Can your only symptom for LPR actually just be one-sided post nasal drip with the other side feeling 100% normal? The sinus CT scan came back mostly clear, mild mucosal thickening (inflammation) of bilateral maxillary sinuses extending up to the maxillary infundibulum on the right side (coincides with the PND being unilateral I guess).