Hey, sorry about your headaches. I suffer from chronic migraines ever since radiation and chemotherapy 8 1/2 years ago.
Medications don’t work for me and I’ve been on Botox for a few years now.
You mentioned your neck pain. Your headache could very well be from your neck.
My migraine care provider started injecting the Botox into my neck on my last visit and it gave me 2 months of relief!
Rather than going to an ENT maybe your primary physician could refer you to a neurologist?
Just my thoughts.

MOJO