I hope you already gone through Fireofx hangs or not responding and still stuck on the problem,if not then please go through. Second as I can't much details about your firefox (I mean available plugins or extensions etc) so it is somewhat not a best shot to resolve on my guess. So can you paste details in reply from Type about:support hit enter from keyboard > Click on Copy text to Clipboard > Paste in reply.

However a general solution is Disable Hardware acceleration from Option > Advanced > General > uncheck checkbox of Use hardware acceleration when available . Restart firefox and see if any changes.

Another thing is that See if your graphics driver is updated from its official sites. Please note that you should not use any third party software which boasts that it will download your system drivers.

Your description means the CPU is being overworked.

Start Firefox in Safe Mode {web Link} by holding down the <Shift>
(Mac=Options) key, and then starting Firefox. A small dialog should appear. Click Start In Safe Mode (not Refresh).

Is the problem still there?

Sorry none of this helps, when I click on the firefox icon on my desktop to start the program nothing happens so I cannot try any of these solutions. It doesn't even open in safe mode as suggested above

Start your Computer in safe mode with networking. Then start Firefox. Try Safe websites. Is the problem still there?

Starting The Computer In Safe Mode;
Free Online Encyclopedia

i actually turned off my laptop and restarted it however im not sure if firefox is in safemode the main point is that firefox is working . i will keep using it this morning and report back if it crashes anytime soon