Glad that I came across this post last night, at a moment when I was struggling with the SOB symptom while trying to fall asleep, after reading a few pages of comments, I felt more relaxed (that I'm not alone!) and eventually dozed off. My SOB (or constantly feel the need to breathe deeply, yawn excessively, nausea and dry throat caused by yawning too much in the cold air...) first appeared in the late fall of 2020 and lasted about a month, like many of you guys described, it can be sometimes intense, but better when distracted. At that time I did blood test for common allergens (like 20+ things) - nothing stood out. Tried inhaler - didn't work, for it kept my attention on breathing, which made things worse. Tested for covid and covid antibodies - wasn't ever infected back then.
Now, after 2+ years, the same symptom came back since about a week ago. Going to see a doctor this week and we'll see how it goes. So far my top 3 suspicions: something related to GERD (in my case I almost always feel minor heartburn & painful throat), allergy related to cold air (both times the symptoms hit in winter, I exercise regularly, sometimes outdoors - and the symptoms get exacerbated), anxiety/stress/panic (I get anxious easily and recently had a few moments of stress, but this wasn't the case when I experience SOB back in 2020). Thanks to all of you for sharing, hope you are coping with it ok these days.