Traveling to China with serious mushroom allergy plus gluten intolerance

I will be in China for two weeks in June on a tour (Shanghai, Yangtze River, Xian, Beijing). I am highly allergic to mushrooms and also avoid truffles. That means, no mushrooms, stock made from mushrooms, truffles, truffle oil, etc. To make matters worse, I am intolerant to gluten, but I do not have celiac disease. So I avoid gluten carefully because it makes me sick and uncomfortable for several days, but at least it's not life-threatening like the mushrooms. Does anyone have any ideas/suggestions on how to stay safe? I think I will be fine on the river cruise portion of my tour (Viking River Cruises), but I think I may be the only tourist who goes to China and can't eat any Chinese food, because I can't trust eating anything that's got a stock liquid or a sauce, is mixed up and I can't identify the contents, etc. (And it's too bad, because I like Chinese food.) Any ideas?