I highly doubt you lost the majority of your muscle mass, unless you had very little fat on your body. More likely is you depleted all glycogen stores in your muscles which is mostly water, making your muscles deflate significantly.
Maybe you're right. It was a long time ago. The only points of data that I have is that I had a "college athlete" level of fat around my heart as per my sonogram and it took me months of work to rebuild my muscle mass.