Hello Melionidas, Please try syncing your devices together and if you don't know how please refer to this link https://support.mozilla.org/en-US/kb/how-do-i-set-up-firefox-sync This will explain how to sync and take a look at this to help you pick what you want to sync https://support.mozilla.org/en-US/kb/how-do-i-choose-what-types-informati... If all this does not work please report back.

thanks for your answer, i just uninstalled firefox, reinstalled it , logged into sync and i somehow got back all my stuff

These add-ons can be a great help by backing up and restoring Firefox

FEBE (Firefox Environment Backup Extension) {web link} FEBE allows you to quickly and easily backup your Firefox extensions, history, passwords, and more. In fact, it goes beyond just backing up -- It will actually rebuild your saved files individually into installable .xpi files. It will also make backup of files that you choose.

OPIE {web link} Import/Export extension preferences

FredMcD said

These add-ons can be a great help by backing up and restoring Firefox FEBE (Firefox Environment Backup Extension) {web link} FEBE allows you to quickly and easily backup your Firefox extensions, history, passwords, and more. In fact, it goes beyond just backing up -- It will actually rebuild your saved files individually into installable .xpi files. It will also make backup of files that you choose. OPIE {web link} Import/Export extension preferences

this looks amazing !! thank u so much