Hi gydoma, what did you reset?

• Inside Firefox, your Master Password: only affects logins saved in Firefox

• Firefox Account password: your old Sync data is removed but you can Sync what you currently have in Firefox going forward

If you don't have Sync data AND you don't have local data, what happened to the local data? Did something else occur on your system? Did you use Firefox's Refresh feature?

Look on your desktop. Do you see a folder called; Old Firefox? Look inside. Look for the folder with the latest creation date.

https://support.mozilla.org/en-US/kb/recovering-important-data-from-an-old-profile

https://support.mozilla.org/en-US/kb/back-and-restore-information-firefox-profiles

https://support.mozilla.org/en-US/kb/how-run-firefox-when-profile-missing-inaccessible

You posted with a mobile device, what is your operating system and Firefox version?

I assume that this is about resetting the password of Firefox Sync account because you mention multiple items?

If that is the case then only a (local) backup of your personal data can recover this personal data. Keep in mind that Sync isn't designed to be used as a backup and best is to backup your profile folder.

• https://support.mozilla.org/en-US/kb/back-and-restore-information-firefox-profiles