Help, I can't get this done. How did it go for you?

Hello everyone, I'm pretty panicked and hope you can give me some tips.
For about two months now, I've had a lot of mucus in my throat and a huge gag reflex. My nose is blocked. I constantly have to clear my throat and cough.
Now my family doctor has referred me to an ENT tomorrow where my sinuses will be x-rayed and my larynx will be examined.
Have any of you ever had a laryngoscopy? And did you do it through your nose or mouth?
I'd take it through my nose, but not through my mouth. I already constantly gag because of the mucus, even though there's nothing in my throat. Can I tell the doctor? I suffer severely from emetophobia (fear of vomiting), which makes my daily life very difficult. I haven't even been able to go to the dentist for two years. I can't even stick out my tongue for more than 10 seconds without gagging.

Do you think if I explain this to the doctor, he'll do it through my nose? How did you feel about it?
Thanks for your answers!!