I too have GERD and I've tried meds for it and the last time I took one, ended up in the emergency room. The meds they gave me are normally given to children but my system didn't want anything to do with it.
When my stomach reacts that's the time I use enzymes tablets, like papaya or DGL. They certainly work in my case.
I started with Loren Cordain's diet and cookbook. As long as I stick with real food (not processed) I do very well. I don't eat grains, soy or gluten, they make me sick, not at first though. If I do eat grains, it starts off with my skin. It feels not smooth with lots of bumps. When I don't eat grains my skin is velvety smooth. I do use Quinoa and non-gluten oatmeal even brown rice sometimes. For meatloaf, meatballs, stuffed peppers... Not often though.
Also added low cost homemade probiotics to my system. These are lacto-fermented foods that have the good bacteria you need for a good gut. It's not a full list only what I like to use. Milk and Water Kefir (water Kefir makes a drink much like pop, but healthy), kombucha (I like the water kefir better, it's much easier to make), sauerkraut, pickles, Kimchi... However, the last three foods use a lot of salt. If you want to cut down on salt add 1 tablespoon of whey to each pint of food you want to ferment or 1 tablespoon of brine from a previous ferment to each new pint of food you want to ferment. Then continue following the recipe. Once, I made so much sauerkraut that I was still eating it after a year and it still was crunchy. And the flavor was so delicious. Note: Using sugar in the water kefir is essential, but the bacteria eat most of it away.
I make yogurt out of milk kefir for even more health benefits. Then make Greek yogurt out of that and use the whey to make the fermented foods. I don't use sugar unless its from the fruit and it's pulp in with my kefir/yogurt then freeze it in these little pop cycle molds. If you want to have it sweeter, then use a little Stevia. They are about 1/4 cup each. It's good for calcium too. So is chia seeds by the way.
People have been preserving/fermenting these foods way before the Industrial Revolution.
I mention calcium because the body needs it. When you get calcium tablets from the store, I found out with research it can cause heart problems and can reek havoc with GERD patience. My doctor confirmed this as well. Remember to take vitamin D it helps with your bones.
Recommended vegetables from Cordain it a very good place to start. I still haven't gone beyond what he suggests. Still there is such a humungous variety of foods to eat.
Using nuts and seeds are a good place to take in good fats. Avocado's are fantastic for dressings. Again I use the homemade milk kefir/Greek yogurt to the avocado.
I know it's hard to find grass fed/roam free meat, if you have a source for that, I'd use it. If not, get the most lean meat you can and enjoy.
All these recipes are found on the internet and it's rewarding knowing the benefits you are eating with the most rich nutrient based foods on this planet.
Hope this helps,
Janie