I’ve had random episodes of strange shortness of breath for a few years too, though all my tests are always normal. I totally relate to that air hunger and the need to yawn just to feel like you’re getting enough. The only things that have helped, honestly, are practicing slow, controlled breathing and trying to avoid mouth breathing as much as possible, especially during stressful times. Exercise helps a bit, but during the really bad phases it almost makes the feeling worse, which can be frustrating. One thing that’s made guided breathing exercises simpler for me is using a device that actually coaches you through them, with adjustable settings and levels. I came across this one, https://omhale.com/product/breathing-trainer-pro/, and I use it especially on days when the SOB feels overwhelming. It keeps my routine on track and honestly makes the whole process a little less tedious.