Anyone healed from loss of muscle mass/tone wasting?

I had a sudden loss of muscle mass after a month off last year. It is getting worse.

 

All my outer muscle and is slack and hanging down.

 

I have not lost weight as always hungry.

 

Can so done reassure me that this is WD and will recover.

Yes, but it stands to reason, I've done practically no exercise in the last year. The worst are occasional back spasms, as if someone thumped me square in the back, leaving me breathless and in pain. I thought I was having a heart attack last time! The plan is to ease slowly back into pilates, but realistically that won't be until the new year.

Thanks! My sudden loss of muscle mass and tone was while I was still doing an hour of Pilates a day.

 

It is very severe.