Mass insanely varying

Here’s my problem: I got sidelined by a shoulder injury (7 weeks ago) that I’m in physical therapy for now. I’m 5ft 6in/180 lbs. The problem is that 7 weeks ago, I was 194 lbs. I’ve atrophied like crazy, but the strange thing is that I’ve kept most of my strength. I thought that maybe it was water weight that I lost, but why would I lose it all of a sudden like that? Another thing is that when I work out, I “puff” (for lack of a better term) up back to the size I used to be. Even all of my gym buddies have noticed it. It’s really weirding me out, and I was hoping that someone that reads this will have a clue as to what is going on and how I can get my size/weight back.

Here’s some speculation that might make you feel better (but it’s not medical advice, okay?) Depending upon your training experience, it’s highly unlikely that you’ve lost 14 pounds of muscle so fast. Unless the injury was severe and a vicious “acute phase response” ensued, you probably have just lost some of the chronic muscle inflammation and water that accompanies hard training. (Hence, you feel small outside of the gym.)Simultaneously, your muscle glycogen reserves may have finally had a chance to replenish with reduced lifting - allowing nice big pumps and maintenance of strength.
I once had a nasty shoulder injury (overuse A-C joint type) and had to BITE the BULLET for almost 12 weeks, staying away from any upper body work other than rehab. I tried to focus upon fat loss and non-irritating leg work and make the best of it. Time is a necessary part of healing.
Good luck, bro.