What tests can get done to rule out any and all allergies? I'm petrified of anaphylaxis and want my normal life back! I can't eat or use anything now!

Fear of anaphylaxis. Agree with Dr Fisher. I will also add that an Allergist can also help to diagnose conditions that mimic anaphylaxis. It is rare to form severe allergy to multiple triggers that could result in anaphylaxis and so a thorough investigation into alternative possibilities is critical for peace of mind.
Allergies. Skin testing for allergies is used to identify the substances that are causing your allergy symptoms. It is often performed by applying an extract of an allergen to your skin, scratching or pricking the skin to allow exposure, and then evaluating the skin's reaction. See an allergist and get tested to see what you are allergic too.