Firefox Stopped Working

Please help me.
I’m using ubuntu 19.4. And its default firefox. Suddenly today firefow was not working I have a internet connection over USB connecting my phone phone. (I’m using mobile phone’s internet) .
Everything is working like Ubuntu software and other software that use internet. But firefox was not working. So tried to update firefox from Ubuntu software, there was no update option only a install option so I click the install button. When firefox installation process is complete I found two firefox on my desktop. When I try to open one, its a new one and it has old history or my old browsing data. Then I try to open other one its also open the same one(not that was I using before).
I have some important password saved on the old firefox that is lost. Is there any way to back my old data ??
Its very important. Please help.


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