Feel like I need to belch but can't start anxiety/panic attack

[F.W.D]

I had a upper GI endoscopy done yesterday to try to get to the reason I can't but a eat but few bits of food without getting a feeling like I have to belch but can't then a feeling of I can't breath that brings on anxiety and panic attack.  My MD gave me Ativan and that helped some and scheduled the endoscopy.  GI doctor prescribed a couple antibiotics, Pantoprazole and sulfam/trim. Waiting for his biopsy test results.
Any one else ever experience anything like this?