the only i can say is try to avoid the foods you are allergic to. My sister is like that she is allergic to everything she loves including chocolate not to mention she is 10 years old so we have a hard time keep her away from her food allergies she doesn't care if she breaks out she just wants to eat so most of the time we end up giving her 1 benedryl after she eats and she is usually ok. You can get the non-drowsy dye free benedryl it will not make you sleepy
Your symptoms raise very significant concerns regarding allergic mediated disease that needs further investigation and drug therapy. Your allergist should be well equipped to both explore appropriate tests and suggest different therapies
I know of someone who is allergic to a lot of different foods. Her doctors put her on a strict diet and she can barely eat anything. they are slowly adding things back into her diet to see what she has a reaction to and what is okay for her to eat. in your case this sounds like the only option you may have. the best thing is to find out exactly what you're allergic to by slowly adding other foods into your diet and once you know what they are, to just stay away from them. it will be difficult because it sounds like what you're allergic to is in a lot of foods. talk to your doctor before changing your diet and he could help you out