If you accidentally deleted your Google Account, you have a short amount of time to try and recover it. If you get the error the account is deleted and no longer recoverable; then you have to create new account with different username. Gmail never recycle the old username.
Recover Permanently Deleted Emails in Gmail. Go to the missing emails support page. Fill up the form with correct details. For instance, email address of the account of which you want to recover emails and messages.
Recovering your Gmail password is fairly easy and to-the-point. If you have forgotten your password and can no longer access your Gmail account, here are a few quick steps to get your account back. Google Account Recovery.