If the main menu bar is missing, see Restore the Menu bar in Firefox, for other toolbars see Navigation buttons like back, home, bookmarks and reload are missing.

As you have explained it is clear that all of your bars got hidden by mistake. And there is no menu bar from where you can enable those bars again. Don't worry it is very simple to get them enabled. Follow these simple instructions!

1. 1: Press "Alt" key it will show menu bar at the top of your browser.
2. 2: Go to "View" option in the menu bar and select "Tool bars" option.
3. 3: It will show you different bars available including "Menu bar","Navigation Toolbar" etc. Now tick the bars you want to enable.

Insha'Allah(Hopefully)! it will solve your problem. The pictures below represent a visual sequence of steps explained above.