I just stumbled across your post and created an account just so I could comment. In 2018, I started experiencing severe vertigo, and that in conjunction with some heart issues for my daughter, caused me to develop severely debilitating anxiety. Thankfully, I’m much better now than I was then, but I still suffer from anxiety and one of my big problems is shortness of breath and hunger for air. I noticed you said you don’t really suffer from anxiety, but I would imagine you are anxious about your sob. Even when you had periods where it seemed better, if you’re like me, you were probably just on edge waiting for it to return. I too have had many tests and am currently taking monthly b12 injections as well as a daily iron supplement. Everything else was relatively normal and I have even been seeing a pulmonologist. I think I will mention the sob to my pcp again at my next appointment though, because I feel like it’s affecting my daily life by keeping me so anxious, which only exacerbates the sob.