Scared to swallow food and afraid he cant catch his breath.

My son is 6years old. He has never really been a sickly kid at all. Pretty normal all the way around. This summer he started complaining of not being able to catch his breath when it got hot and he had to have a bottle of water when we were in the car. Not that he would drink too much of it at all, he just needed it. After a few weeks those issues seemed to go away. Skip forward to about a week ago. Things have kicked up again. This time he's complaining about being afraid to swallow, that he will choke. He's been saying that he wont be able to catch his breath. I will notice him sitting there watching tv and he will just take a gasp of breath and then be fine. This happens all throughout the day. He barely ate any breakfast, a 1/4 of a sandwich for lunch and about 4 full size bites of dinner spread out over about 10-15 tiny bites all the while crying that he was going to choke. He has no problem swallowing liquids.
I'm really scared for him as this is more real for him than any other time as I can tell by the intensity of his panic. I've tried raising my voice to him, making him stay at the table after all have left and he will not budge. I was hoping that by doing that I would have called his bluff had there been any. If any of you can help me with this it would be greatly appreciated. thank you.