I would stop the Flonase for a while, I have heard that you can get a rebound effect from using decongestants too often, and this can gum up the progress of cleaning the tubes out.
I'm getting a referral on Sunday, and going to a specialist at the end of next week, it's been three months and I'm still waking up to the same noise every single day, although the daytime and evening symptoms have improved somewhat.
I don't understand why your doctor won't give you a referral, mine has never refused to do it for any reason. Did you ask for a referral to a specific doctor you found, or for him to suggest one? If you can, do your own research and find one in your plan, and get the doc to refer you. I would suggest that it does not have to be an ENT, if you can find a specialist for Otology and/or the related fields of Neurotology and Otolaryngology. Good luck and keep us posted.