Suggestions for a restricted diet?

I am trying to switch to a veggie-plus-fish diet (still eating eggs and small amounts of milk and cheese). The problem is that I have a very easily upset stomach, and my GI has forbidden me to eat most veggies (including asparagus, cauliflower, cabbage, brussels sprouts, green peppers, onions, radishes, corn, cucumber, broccoli), many fruits (mangoes, melons, bananas, avocados, apples), and worst of all, all legumes (tofu, lentils, falafel, peas, peanuts and peanut butter, cashews). This cuts me off from many of the protein-rich staples of the veggie diet, and I find myself eating a lot of fish and babaganoush.

Does anyone have suggestions for alternatives to some of the things I mentioned that are easier on the digestion, or things I might add to my diet that I haven’t thought of? I would love a peanut butter substitute – I tried tahini paste but it’s sooo dry. Has anyone tried tempeh? I have heard that it’s a preparation of soy curd that’s easier on the stomach than tofu, but it’s really hard to find.