Well your wallet is where you keep your coin safe and it always important to protect it
One of the best way is to protect your private key never give it out to any one even if it's your mentor that is very important
This is for new guys like me
You can also try some different ways of logging in into your wallet. In myetherwallet, there is a feature where you can login offline, and also through the use of JSON file, just upload the file and enter a password, through this, you can log in without the need of your private key.