@laurasue The method is called Buteyko Breathing Method. The best way to learn it is through an online instruction through this organization based in the UK; https://learnbuteykoonline.net. It costs a little bit of money (around $300ish) but well worth it. I think it will help you. It won't cure you but will make your condition much more manageable. You just have to make sure you follow and are diligent about the exercises. It's a lot of breath-holding which can at times be uncomfortable, but you're essentially retraining your body to breathe less, which helps you breathe more normally.