Allan, so neat that your visit with the kiddo was nice! Always a blessing.
As to the breathing, sounds like MG to me as well. I remember way back when I was not even a year into MG, I got aggrevated that I couldn't do things anymore. So I got out the lectric mower (we had riding mower for the acreage, but the push mower for around the fences and tree line and such.) Not a big job at all as I remembered it. Anyways, everyone was somewhere. I pulled that blasted cord half a dozen times till the mower finally kicked over. Off I went being very careful to walk slowly and leisurely mow. After 5mins or so, I could barely stand up. I had to almost crawl back into the house. Breathing was tanked totally, arms and legs were nothing but jello. First and last time with MG I mowed with the walk behind mower.
We have to remember that when we use our arms...we are also engaging the muscles in the chest. So they weaken right along with the rest of our muscles.
do touch base with the doc on your next visit (so long as you are having no further issues that need IMMEDIATE attention) with the doc.
Try to take things easy. STOP---THINK----THEN move forward if all evaluates out to be doable.
Hugs
Deb