I have two little boys with about the same host of allergies as your boyfriend. My wife and I make a lot of Thai dishes with rice noodles. I understand the lactose issue but fruits have much simpler sugars and normally shouldn't be a problem although I do know a couple of people with berry allergies. Has he tried coconut milk or any of the others (rice, soy, hemp...) I prefer the coconut and use it as a substitute for regular whole milk whenever I can.
A lot of the gluten-free blogs have good recipes too, but gluten free doesn't mean corn free so make sure you read the fine print. I made a really good lentil dish the other day with a wild and brown rice mix from Bob's red mill and some green lentils from the health food store. We use tinkyada brand rice noodles since they seem to be the most like what we're used too. They have a pretty good spaghetti which the kids really like. My wife makes some pretty killer spaghetti and meatballs.
I suggest investing in a good wok, maybe a rice cooker, and explore Asian cuisine to add a bit of variety to the same old, same old fare. I know it's difficult at times, but eventually you'll discover stuff that he can eat and find substitutes for things that you crave.
I hope I helped a little bit. Hang in there!