Might be a bit random, and perhaps a bit far fetched, but are you able to burp?
I've been struggling with the same thing for most of my life and was diagnosed with R-CPD ( retrograde cricopharygeal dysfunction a couple of months ago. Fortunately there is a treatment that is as good as 100% effective for this diagnosis.
(No burping = excessive flatulence)
Botox treatment scheduled for March/April next year, but I will try to remember to update you when it's done!