Suggest Treatment For Redness On The Face And Itching On The Extremities

Question: Dear Doctor,
I have this chronic problem that started in 1998 when I ate some honeydew melon. I became very sick with a scratchy throat and my palms and soles became blotchy red and very uncontrollably itchy and swollen. I also had diarrhea and vomiting. I've eaten honeydew melon since and have been fine.
Since then I have had at least 20 episodes of this, and most of them in the past few years. Each time I have an episode the symptoms get worse. I have had 3 episodes this week alone and they have been the worse I've ever experienced.
Along with the previously stated symptoms, I am now having a burning red changes in my face, neck, and ears which become very uncontrollably itchy and swollen like my feet and hands which can look "doughy." Also, I get hives and large red welts on my torso. I become very weak all over and have to crawl to and from the bathroom. My heart races and my sight becomes dark as if I am going blind and sometimes I will see green "squigglies." Once the vomiting and diarrhea are over, I either crawl to bed or lie on the floor and fall asleep. Last night I had all of this plus fever and chills.
It always happens after I've eaten something: plain boiled potatoes, baked sweet potatoes, watermelon, carrot ginger soup, papaya, carrot cake, nuts, seeds, lentils, pasta with red tomatoes from a can, strawberries, cantaloupe... Last night it was the carrot ginger soup, but just because that happened to me, it doesn't mean that any/all of these foods will make the episode happen again. I never know what foods will do it to me or when.
I once was able to drive myself the the ED where I was given an IV of antihistamines which I take and carry with me. To me, if it was a food allergy, wouldn't it be the same food(s) all the time? I've tested (-) for celiac, but now I am wondering if this is "leaky gut syndrome." I have also been tested for allergies and the only (+) result was that I am allergic to dust mites.
I am a 51 y.o. caucasian female. I eat and live a healthy lifestyle (no drugs or cigarettes, and I rarely drink because alcohol gives me an instant headache so it's rare I can finish 1 glass of anything). I have no other medical problems (including history). I would love to know what is wrong with me, how to treat it, and hopefully cure it. I am very worried about this and would hate to be found lying in my own mess dead on the floor someday (yes, you can laugh at that!)!
Thank you,
XXXX

Thank you Dr. Deepashree! I greatly appreciate your time and help. I will look into this ASAP.

Thanks again,
XXXX