I can't forcequit firefox and shutdown my computer, nor can I open up any other programs or applications. Does anyone know how to fix this? please help this poor soul.

You can force quit applications

>Force quit

if that does not work you can force quit a computer shut down by hold the power button for an extended period.

This is by no means a "fix", but rather a workaround. Try opening your terminal (Launchpad -> Utilities -> Terminal).

Once in the terminal, type these commands (it will ask you for your administrator password, it's normal to see nothing while typing):

sudo killall launchservicesd

sudo killall Dock

After that, the Firefox icon should be gone from your dock.