You should NEVER use your master key for carrying out any kind of activity in your account. The master key is literally your last back up to your account.

I learned this lesson pretty early when I first started out even if no one told me about it. The first rule of Steemit is to not lose your keys.

If you lose your posting key or active key, you can gain them back using your master key, but if you lose your master key, it's pretty much over.

All your progress and hardwork goes to trash and since Steemit is still in beta and they can't do much to help you recover it once you lose it.

My advice is to write all your passwords in a paper and hide it somewhere safe in your house so you don't lose it because of technical problems in your phone or computer or whatever.

But with that said, that experience taught you a valuable lesson and I hope you won't ever repeat that mistake again.

It really bothers me when I see people lose all their progress like that because I've experienced similar things in my life too.

Keep you keys safe. And your master key safer.