Hi Dan. Many folks have resolved or at least improved their GERD/reflux by eliminating grains completely, particularly wheat. Have you tried that? If you’re already eating low carb, you’re most of the way there, but you have to read labels like crazy and be careful of cross-contamination if you’re cooking with others in the house.

I’m familiar with that trying-to-sleep-upright discomfort and it’s one of my consequences for glutening myself.

I haven’t read “Wheat Belly” by Dr Davis, as I was already eating gluten-free when it came out, but I think he goes into more detail about it. Someone else might chime in here with a better explanation.