I had a very similar episode last year and it lasted for at least 6 months. I had been diagnosed with GERD about 2 years earlier, but I had finally started feeling better, so I stopped taking my PPIs. I also kept smoking (not great, yeah). I started having these breathing problems and for a while I didn't even think it was my stomach or the GERD. I couldn't get a full breath in and was always short of breath, my chest always get tight. At first I thought it was anxiety. But when I kept having post nasal drip, I realised that was likely not it. My nose was also blocked ocassionally. I started taking PPIs again when I realised it was my GERD that was giving me breathing and sinus problems. My advice would be to to go for a strong PPI, and a high dosage too, try a different one if the one you are on is not working well. It got better very slowly over time, I honestly thought I would have to deal with this symptom forever. However, I also have a good diet and don't eat anything acidic and rarely allow myself any junk food, which is why it might take longer for you to see an improvement. I do believe that episode got triggered by me drinking and smoking quite often at the time, and exercising a lot, often right after eating. I ended up quitting both smoking and drinking. altogether to star