My son is 6 months and breastfed; I have been on a restricted diet for 2 months...no dairy, soy, wheat, shellfish, peanuts or tree nuts, eggs, and citrus. The doctor allowed me to have citrus, but within a few days, he already has a red bottom. Hopefully I will be allowed another item at his next docotors visit because I am going crazy! I have basically been eating meat/fish, fruit, veggies, beans, and potatoes and boy does this get old fast especially when you need to make a quick lunch and a sandwich is out of the question. You are right, almost everything contains wheat flour or soy and a lot of prepared food contain dairy, wheat, and soy. I do not have any suggestions as far as food goes, I just read the labels, which it seems you do as well. I just wanted to let you know I feel your pain.
I do not know your experience, but my son was constantly throwing up when he was about 1.5 - 3 months old and having a lot of gas, then his neck started to get red and rough, he had eczema all over his back, and had constant diaper rash. I kept asking the docotor what was going on and of course it was oh, he just has dry skin or that rash on his neck is from drooling...so I finally looked up all the symptoms on the internet and immediately stopped eating dairy and eggs on my own (I did not know about the other foods). I then went back to the doctor and talked to the lactation specialist who immediately said "Oh this is a protein allergy". It was really frustrating, knowing something is wrong and the doctor not really listening.
I do believe if you type in MSPI (I did not know this is what it is called until now, so thank you) in google, you will get quite a few results and possibly some recipes.
I think that most kids do outgrow the allergy by the time they are 2 years old and boys are effected more than girls.