Hello.
I think it is perfectly reasonable to ask for help without spending another few thousand dollars. Maybe you could try some medications to see if they help? I use cerenia drops often. I also try a nasal flush under general anesthesia. This is a really hard place to look at our even investigate. So I would give some time and some medications and see if that helps.
If all else fails ask for a feline specialist referral.
Good luck. Keep me posted. Please.
I would contact your vet and make them aware of this new behavior right away.
I would worry this is pain. Or stress. There are lots of medications available for these. Please call your vet.