It is possible to be allergic to white rice, but see how it goes. Chicken is usually okay. Any grain you've rarely eatten, like buckwheat perhaps or quinoa since you're in Europe, is a very good choice. Same for meats. If your body hasnt been exposed it's less likely to be allergic.
There is a Small chance that if your gi is that farked you could develop an allergy right now to a new food (my farked body decided it couldnt handle the american staples of wheat and corn).
Foods low in protein like potatoes and tapioca are generally safe. You can probably google the least allergenic foods.
To make matters worse, it's not just what you eat or the proportions you eat, but the foods effects on you. Take ginger for example. Great for nausea, right? Well if your GI/stomach needs to go downward (er, the food and energy need to go down) then its great. If you are like me and almost never vomit nor feel like doing so, ginger can make your gi an even harder knot of pain. Ask me how I know.
Some foods, like buckwheat are cooling. Great for me in the morning when I run hot and can walk around my house half dressed. Bad idea when I run cold every night and cant circulate heat to my hands.
You can google TCM and food for more. Trying to figure out what food you need is hard though, so consider a TCM practitioner who specializes in food. Avoid herbs until you see your normal doctor unless you feel comfortable with trying them (based on someones recommendation, not just trial and error!)