There's nothing anyone can do here since you didn't make any backup of the firefox browser user data, profile, bookmarks or login to restore back. Sync isn't a backup tool it's sync between device to sync server to another device that all it does. If you logged in with the new setup it wiped clean any data on the sync server with the new data.

dam that sucks thanks for the help

diazjayden890, sometimes Windows will keepp some user data after a reset, depending on the options chosen.

Do you have a (possibly hidden) "C:\Windows.old" directory?

If you do, then your Firefox profile data might be recoverable from there? Sorry, but I am not an expert on Windows resets and where it saves any user files tht it keeps.