What you're describing is a lot like how I felt when I first started having panic attacks a long time ago. I felt like I was dying - it literally felt like I couldn't breathe. But as my therapist at the time pointed out, no one has ever died from a panic attack!
Your airway closes briefly when you swallow food because of a little flap that covers it to keep what you're eating from going down into your windpipe. That's how our bodies are designed - if we didn't have it, eating would be a dangerous affair! But you can breathe and eat at the same time, right? Just not at the precise moment when you swallow. That's how we're supposed to be.
If your airway is truly blocked, you don't wonder "what if?" If you can breathe, talk, eat, etc, your airway is not blocked. If you can sit and exist comfortably, your airway is not blocked.
Anxiety is a bitch, but that's all that you're suffering from. Your airway is fine. Your brain is the thing messing with you!