I could barely breath for a few weeks, got xrays and an asthma sprayer and everything, woke up breathless and panicking.

Then it went away when I finished a big work project, and it became clear that it had all been caused by anxiety. It's wild and not to be underestimated. Every few years I get some random pain which tends to go away after something stressful is finally finished. Some subconscious part of my brain just decides to over-fire and there's not much I can do about it except not stress about the stress response and make it worse. The worst thing is that it makes it harder to finish what is currently causing it.