Try to install Firefox using the steps at Installing Firefox, does that work?

Same issue here, my firefox is all messed up. I went to update it and now I cant even load yahoo mail, google, ect.... it just crashes everytime.

Now it wants me to install this plugin-container from mozilla. I don't wanna unless I know for sure it wont make things worse.

Wouldn't I have to delete my current version, to install Firefox as a new download as the link Installing Firefox suggest? I would be starting from scratch then? What about bookmarks?

Make sure to not delete your profile folder which the re-installer doesn't do by default, then the settings/bookmarks/preferences will be saved.