I find myself stuck because my MC is having a panic attack, and I can visualize this all very well from the outside... but since he's my POV character I need to know what's going on inside.

The situation: About two weeks previous, my MC was caught in a huge crowd and trampled badly. He panicked a little at the time, but then shook it off. He was bruised but otherwise okay. Now he finds himself at a small town parade. He was a little nervous about the crowds at first but since everyone is sitting down watching the parade he is fine. But then after the parade he and everyone else head toward the fairgrounds. So it's a kind of big, loose crowd - not dangerous - and he keeps telling himself he's fine, but the crowd gets tighter and in the end he's going to panic.

So can someone describe for me what this would look like? How does it feel, both physically and emotionally? Would he be confused, heart beating fast, what?

Also I am wondering if he would have the presence of mind in the midst of this to be really pissed off at himself for letting this happen. His girlfriend, who pulled him out of the first stampede, is with him, and he's trying super hard not to look like a total wimp.