My ideas about my own diet changed a LOT once I found out that my son can't have wheat, dairy, or soy. Since nearly all pre-packaged food has one of those things, I was forced to learn how to cook from scratch for the first time. I wouldn't ever go back. It takes some adjusting but if you limit yourself to the produce, meat (fresh, not processed), and dairy sections at the grocery store you really will find everything you need. All of the other aisles become unneccesary. Get yourself a good cookbook and go for it
Some other good places that I've found to be valuable in my health journey are www.mercola.com and www.westonaprice.org. And a great documentary is Food Matters.
Just go forth from here! You've got some big strong babies and that's great. The rest of their health depends on you. Blessings!