Hi Gabriel, I have a question for you. Doesn't singing make your breathing problem worse? Because if I sing a little, this breathing problem becomes more severe. Maybe stomach acid has damaged the larynx for a long time and this tension is to compensate for the damage. If you can go to a laryngologist and describe your problem completely and take a picture of the larynx. Maybe where you are, doctors will have more knowledge and the root cause will be discovered