Hyper elastic skin. Hyper elastic skin?

Hi, Background: When I was 18, I weighted about 82 kgs. Then I went to hostel and lost a lot of weight (due to bad mess food). I started gymming 2 years back while in hostel itself. Problem: I am having loose skin on my body. When i go to gym regularly for 5-6 months, i am able to build decent muscles with reduced loose/elastic skin. But after that even if I skip gym for 10 days, I have lost muscle mass very fast, to the extent that I become skinny. And then again, the elastic skin appears and i appear weak. My question is weather there is a problem with my skin being elastic ( is this some inherited condition like Ehlers-Danlos syndrome or due to loss of weight). Also, why am i losing muscle mass so rapidly given that i eat eggs and take protein supplement after the workout. Is it because of the possible hyper elastic skin ?? Any suggestion on what should be done would be quite helpful. Thanks