Hi Alex. Good to hear from you. I'm glad the tests at least ruled some things out. Probably still frustrating that it didn't lead to anything definitive, but also good that these tests rule things out.

Was the sinus pressure something you've dealt with, or just due to the endoscopy? I too had an endoscopy done a while back, but they were able to numb my airways. Though I still did feel pressure, it wasn't unbearable. So I'm wondering if there's some sinus inflammation there. If so, that could lead to breathing issues.

So to answer your question about the breathing technique I'm using- it's the Buteyko Breathing Method. I believe you may have tried it out to no avail. But I just wanted to offer that if you decide to give it a second chance, the "true" way of doing it involves commitment, determination, and learning. When I treated it like a bandaid and just did to alleviate symptoms, that didn't do much for me at least long term, but when I applied the techniques diligently and throughout the day, that is what helped me.

I went through learnbuteykoonline.net, which is an organization based in the UK I believe, and they have practitioners that know the method as taught by Dr. Buteyko. There are other practitioners all around and books written about the method, but I wanted to learn as much of the full method as possible. So just something to consider.

When I first started learning, I would apply what I learned in class; that is- focusing on nasal breathing only, taping my mouth shut at night to avoid mouth breathing, light to moderate weight lifting using only nasal breathing, no extremely heavy cardio exercise, the "rescue" exercises, steps (while breath holding) exercise, measuring Control Pause, etc. So there's definitely a lot, but when all put together I believe there is some benefit there. It may or not my cure you per se (I hope it does!) but certainly would help in managing symptoms to where they may not be bothersome anymore. But as I said, learning the true method takes devotion and patience, as these things would need to be done throughout the day until your body becomes used to the new breathing habits.