I thought I was writing this for a moment, though I don't really get palpitations.
I have a Haitus Hernia and eosinophilic esophagitis, so I often end up with a lot more burping or belching than most other people I know. Stressful situations do tend to make me tense up too, even if I'm not aware of it, as it usually results in either a few bubbles or a low drawn out belch. To avoid being embarrassed by it, I guess I started finding a way to make it come out more silently, by positioning myself a certain way to let it come out quieter? Kinda like a silent fart :P.
I had GERD and was taking the typically prescribed meds in the past, but after doing a low FODMAP diet, and identifying broadly what foods and how much cause me more gas or reflux (for instance more than one slice of watermelon gives me gas, and a single slice of rye bread gives me reflux), I have not needed them. I also found out that much of my reflux was not food related, but anxiety related (e.g the drive to work, or having to present something).
When I have any anxiety-inducing events coming up, I avoid eating too much before, to avoid creating more issues. If you haven't tried an elimination diet designed to identify what causes gas the most, I'd definitely recommend it - I went to a nutritionalist to do it. I found that knowing what foods or drinks gave me reflux, reduced my anxiety in certain situations because I knew I could control the gas, by avoiding certain foods in the lead up to something that I was worried about (because the feeling of trying to talk over a bubbling bit of reflux is anxiety-inducing enough!)
When anxiety builds up during the week for me and I know my whole body is tense, I like to go get a massage, or go for a good long walk in a rainforest or mountain area, I find it super soothing. The smiling mind app is also pretty great for relaxation. The best trick I've found for my anxiety, is a good several hour distraction.