I'm sorry you are going through this. I'm not really qualified to answer, but I've experienced a lot of your symptoms, especially the sudden allergic reactions to foods I have always eaten and symptoms worsening during stressful periods. I was merely diagnosed with idiopathic food allergies , which is bs in my opinion. I think in my case it is several different things: parasites, candida, heavy metal toxicity and adrenal fatigue.
My advice is to try some cleanses,starting with a Bowel Cleanse to open up the passageway so that if you opt to do other types of cleanses ( liver, parasite, etc) there is a clear path for the toxins to be eliminated out of your body. It helped me tremendously and I'm now able to eat everything again, although I'm in no way cured. It's a long process. Something else that helps me is a lot of greens. I love Green Vibrance powder because it packs a lot of punch in one small serving. I also recommend soaking in a bath with 1 cup epsom salt, about a 1/4 cup baking soda, 1/2 cup raw apple cider vinegar (with the mother) and a few drops of tea tree oil (skip the tea tree oil if you have sensitive skin). Just submerge as much of your body as possible and sit there for about 20 min. Don't use soap or anything else-- just soak. Rinse off quickly in the shower afterwards, but soap will lesson the effects of the Epsom Salts , so try to avoid it immediately after the bath.
I think these are very easy, cheap and safe options to get you started on the road to healing, but others more experienced may be able to give you some other more effective protocols. I think you have more than just one thing going on so try to keep an open mind. It's extremely hard to do while dealing with these symptoms, but you have to reduce your stress --- you'll never heal if you can't get your stress under control.