when I added the extension on a different laptop and I tried to access my account, metamask asked me to insert a new password and to confirm it OR to insert the 12 words phrase. I had not the 12 words phrase (having to leave my home and not imagining I will need the phrase or private key so soon), so that I inserted the same password I had, as a new one. And I was expecting to find my ETH address, filled with the ETH I had...But no, metamask created a new ETH address in which I had 0 ETH and a new 12 words phrase. In that account (accoun 1), at the top of the page, the new ETH address had a link (which contained the new eth address too) . Then, in that link, I replaced the new ETH address with the old ETH address (which is connected to Empowr). And I refound the old/initial ETH account/address whereI had some fractions of ETH....However, I do not have the private key for it....and I need it urgently. Also, that old ETH address does not have an account (Account 1, account 2 , account 3 etc) corresponding to it, so that the new ETH address has I need to import the old ETH address/wallet and I need its private key...So, Can you help me with this to know what to do ?
You'll need your Mnemonic Phrase
Unfortunately, without your Mnemonic Phrase (or a backup of your private keys) there's no way to recover the accounts. So you'll need to get that phrase off your other computer at a convenient time.
Once you have the recovery phrase, you'll face another problem, how to enter it into the new MetaMask instance once it's initialised...
Resetting the vault.
Once you have initialised the MetaMask extension, there's no built-in way to reset the vault using your original seed phrase.
If you want to start from scratch, you'll need to uninstall the extension and reinstall it at which point it will ask you if you have your seed phrase available again.
This will however result in the new vault from being destroyed and replaced with the old one, which may or may not be desirable.