When I first got MG and didn't have a diagnosis yet, I was very weak and stayed in bed most of the time...I was only able to move around for about 10 minutes at a time for a few times each day. I was in really bad shape, and every time I woke up I had tingly arms, face, legs. I remember feeling out of breath but not gasping for air like you described. I probably should have gone into the emergency room at the time, but I didn't understand what was happening, the MG came on so quickly.

This problem went away over time after I started to take Mestinon so I thought it was MG related, maybe I was sleeping too long in one position.

I think you should call you doctor as soon as possible if you haven't already. It is no fun to be afraid to go to sleep.