Hi Alison,

It sounds very much like panic/anxiety attack, more than allergy reaction. Do your lips, chin, and/or face turn red, swell up, or have bumps (hives)? Does your throat get itchy and feel 'smooth', not just swollen? If yes, then most likely you have allergies. If no, than most likely panic attacks.

I have food allergies, and sometimes I get panic attacks, so I know the difference. One way to help you get past the fear of being allergic to food is to keep telling yourself you're not allergic. That's helped me.
Good luck.