I get this same feeling fairly often, and I think I know what my pain originated from.
Just a quick description of my pain: suddenly I will breathe in and feel an extremely sharp pain , like a knife, stab into the back of my neck. Sometimes the pain is so quick and intense that it feels like it shoots down my chest. It can happen a few breaths in a row, sometimes only once, and the other day it kept happening every time I breathed in for about 15 minutes. It's awful and terrifying. I always feel afraid that I'm going to die, especially awaken it happens when I'm alone.
However, I did a little research, because I get pretty bad acid reflux, and often food gets stuck in my throat. Also, especially lately, I've had to burp a lot but it's really hard to burp - it's like my throat doesn't want to let in or anything out!
It turns out that when I drink fuzzy water, like San pellegrino, I'm able to burp and the pain goes away. I believe that my pain is entirely to do with my digestive system, indigestion, and acid reflux!
I saw this website that explains the difference between cardiac pains versus gastro pains, and this really put me at ease. Now I just stand up, walk, and drink a bit of pepto and it helps a lot.