Hello, I have read some previous entries and I have also put some theories on the table in the past.
Without a doubt one of the parts that I have already mentioned that most have is inflammation and the creation of phlegm in the throat, but for me this is a consequence.
The problem is in the stomach, but there is something we do on a daily basis, which we are probably not taking into account, which is to breathe with the diaphragm. Probably only when we remember it is when we breathe correctly. There are several problems that arise in the nervous system, consequently in the sympathetic and parasympathetic systems.
The point I want to get to is that to remember and be measuring the oxygen I just bought a SmartBand (Honor Band 5), it can be any watch too, the important thing is that it brings oxygen monitoring and that periodically (every half hour) put a reminder, so that the band or watch reminds us to perform diaphragmatic breathing.
The same anxiety and stress about not solving this, worsens breathing and affects the other systems.
I invite you to try this, to put comments here. Greetings and keep fighting.