Site just died out of the blue - not even sure how to debug what happened

I setup a 10$/mo droplet, running a WordPress install.

Things went smoothly, I encountered no issues and was able to get everything setup quite easily.

fast forward 23 days, and my site is now hitting a 504 - Gateway Time-Out error.

I reached out to the digital ocean staff (not expecting to get much help - which I didn’t) and was told to run ‘top’ to check what processes are running on the server.

Yesterday, around 7:00PM EST, I can see in the chart that’s when my CPU usage started jumping from about 15-22% to 100+%. I haven’t logged into the site, sshed in, ftped in, made any alterations etc.

I’m wondering why would my site just start spiking north of 100%, when I’m not receiving any more traffic than I normally am.

I’m at a loss here - and the sites been down for over 24 hours now, and I’ve made little to no progress in debugging it.

Thinking it might be time to call it quits and transfer away from DO - due to the down times.

Thanks to anyone who is willing to shead some light.

Graph Screenshot: https://cldup.com/o-1AVekaMv.png

You can see, that in the past day is when everything started going haywire.