I was prompted to upgrade to Focal Fossa. After a while progress froze, went to bed to give it more item to update. 7 hours later still frozen on same screen. Hit power button (Did not know [Ctrl][Alt]+[SysRq] REISUB existed at the time).
Boots up to the Ubuntu loading screen. Then it loads up a black console for about 1 second, power cuts off to the monitor for a second. This repeats. I will test newer Ubuntu upgrades from a USB stick from now on. Currently using 18.04.3 boot stick on the only USB I have available.
What steps should I take to repair my system?

Thanks in advance.