If there is nothing worth downloading from the FF sync account and instead have all your user data on your current machine, then simply create a new FF account for syncing via a different email address.

I assume that the OP want to restore the passwords from the Sync server since they mention "my password to email is saved in Firefox sync".

Can you login to the Firefox account via this web page?

• https://accounts.firefox.com/signin
• https://accounts.firefox.com/settings

Are there other devices connected to Sync ?

Note that Sync isn't designed to be used as a backup, but is merely meant to sync data between connected devices.

You can install the About Sync extension in Firefox 72 and newer on desktop to check what data is stored on the Sync server via the about:sync page provided by this extension.

• About Sync https://addons.mozilla.org/firefox/addon/about-sync/

Close and restart Firefox to access the about:sync page added by this extension (see the about:about page for possible about pages).