This may work, may not but try removing ALL external cables from everything on your computer - power, peripherals (printers etc.), monitor, everything. Leave it for a while - this is just so you can collect yourself and calm down. Then reconnect everything very carefully.
This doesn't do anything more than connect everything up again but there is just a chance that you've got some cable loose or the wrong way, you know the sort of thing. This procedure has worked for me in the past, it may work for you.