Next time you forgot your seed phrase, you don’t have to uninstall Metamask and create a new wallet. If you still have Metamask installed you can find the seed phrase if you follow this guide
You say you need the 4th account ? Did you add some money to this account ? Did you install/delete Metamask 4 times and got 4 different seed phrases ? or did you create 1 wallet with many sub-accounts
I have money on the 4th account.
I deleted and installed MetaMask more than 4 times and each time forgot to write down the seed.
(Different seed phrases cause it was different accounts).
And now i dont have acces to the 4th account.