next time use MOZBACKUP..i dont know any other way. in your situation idk, if iweru i would research that possobility. also if u use lastpass it stores the info online so it always remembers ur passwords.

i need to go back a day on my firfox so i can get my passwords back can i on a browser and not my computer

You should never tick the box to remove personal data if you uninstall Firefox unless you have made a backup of files in the Firefox Profile Folder

• http://kb.mozillazine.org/Profile_folder_-_Firefox

You can try to restore that profile folder with an undelete utility like Recuva.

• http://www.piriform.com/recuva