Is wearing a mask and staying away from the world destroying my immune system??? covid isolation

No: In many countries around the world, people wear masks or face coverings when around other people, and their immune systems are just fine. Also, with this pandemic, a person doesn't have to stay away from the world. He just has to stay far enough away from nonfamily members so not to catch the virus. That means living wisely is just as safe as living like a hermit, from a public health perspective.

Not hardly!: If is protecting your immune system from something that it may or may not be prepared to deal with. It is also protecting other from you if you become ill. Their immune systems may not be as strong yours.