If this were me, I would backup my whole site via FTP and download a backup of my database.

go back to your ‘mysite.com/wp-login.php’ and see if you can reset your password with the ‘forgot password’ link on that page. (if that was the case)

If no progress,
Go to your phpMyAdmin – or whatever your host uses to manage your database – and look at the wp_users table to see if your admin credentials are still there.

You can create another user manually through your database manager (phpMyAdmin) with SQL queries if you wish.

Good Luck!