I have the same issue as you except your terrified of throwing up I'm convinced that I'm Allergic to everything and I'll stress for 2 hrs after eating something constantly check my throat check my heartbeat per min chug water it's awful. It's paralyzingly and it's hard because I'm pregnant and I need certain vitamins and nutrients for my baby. Even if I have had it before it doesn't matter because an allergy can occur at any time. Some days are better then others but it's awful there's days I tell myself I'm never eating ever again. I have a constant fear of my throat closing up and I'm pretty sure that's where this phobia of being allergic to everything comes in. It doesn't matter what others tell me I cant shake the feeling of complete dread. I have dealt with anxiety and panic attacks for awhile some months I'll be great then I'll hit rock bottom again and each time y hole keeps getting deeper. Idk it's hard and I can def relate to you. Feel free to msg me back. Maybe we can help each other get over this horrid issue.