Hi Seacoasthalo!
I am NOT a doctor -- nor do I have any medical training whatsoever. But, your fiance's symptoms sort of sound "familiar". Has the doctor mentioned ALS? In the beginning, it is VERY hard to tell the difference between MG and ALS. In fact, sometimes it takes MONTHS before they can figure it out.
I am hoping and PRAYING that ALS is QUICKLY eliminated as a possibility. But, as I've recently been told by several members of this group -- KNOWLEDGE is "power" -- so, on the "off chance" that this might be what you are dealing with...............you might want to wander over to the ALS forum and repeat your post.
You and your fiance will be in my thoughts and prayers!!! And, PLEASE keep us updated -- we really DO care!!