Hi idawmn and welcome,
I am sorry to hear of your recent breathing issues. I know how miserable that feels. I did have this as one of my anxiety symptoms early on in my experience, and I remember how awful it was.
I am glad to hear that you are getting everything checked out from a physical standpoint, as this is always a good first step...and I hope that your upcoming appointment reveals some answers for you.
Until then, and in case this is actually anxiety related...I am going to post our Resource link here. It is full of great self-help coping tips that you can try for the time being, and see if you start to feel relief.
The stress relief exercises should be especially helpful to try.:)
https://www.healingwell.com/community/default.aspx?f=9&m=104206
I hope that you get the information that you need to seek treatment for the cause of your concerns, and start feeling better soon!
Post anytime,
Scaredy Cat