Here are my thoughts wild_cat:

What day is your neuro appointment?
Do you have people around you when you are the most anxious?
Are you on any medication now?

I canīt give advice but can tell you that in my case my open minded GP prescribed me Mestinon, and whilst I was scrutinizing itīs effects on vision problems it also surprisingly greatly relieved diaphragmatic muscle weakness 20 minutes after dose. For sure it does not work on everyone. My symptoms are milder but I can count on this medication working consistently with my breathing muscles until I get a pulmonologists appointment. (I need a break from the neuros ) But I never ever expected it to do such a great job.....hang in there.....keep in touch.....