Hi Gabriel, do you still suffer with this? I can see everyone's comments but from my own experience and countless research if you haven't found the cause based on everyone's comments im like 99% sure this sounds like laryngopharyngeal reflux disease/respiratory reflux. This would make sense with your GERD diagnosis/be the cause of your sinus issues, cause your shortness of breath and many other issues you describe. LPR is a complex beast and it is really understudied and under diagnosed. If you look up the symptoms I'm sure you may get why I am posting this. Most drs don't know much about it and patients (I am just like you) see basically every specialist and get the all clear, respiratory, heart etc. The only way to really manage it is diet and lifestyle changes that would also help your GERD. Ppis can often have little to not effect on lpr and sometimes make it worse. I too have lpr and no one understands what I mean, I'm constantly gasping to get air in and it feels like nothing is working and I'm still out of breathe. It's much worse when I'm trying to eat. I won't list every symptom I've ever experienced because the list is endless but changing my diet dramatically made a world of difference. Sadly allergies, illness etc make lpr flare up but can get it much more manageable through diet and lifestyle changes. Look up Dr Aviv and Dr Jamie koufman who are experts in LPR. I hope you have found relief since 2019, I for sure know it is a nightmare rollercoaster and it's hard to find any relief. It's endless.