16GB server shutting down very often

Are you sure your droplet is shutting down and not simply apache or mysql crashing? Check both of their error logs and see if you can find any pointers there.

Before tinkering w/your droplet further, make sure to take a <a href=“https://www.digitalocean.com/community/articles/digitalocean-backups-and-snapshots-explained”>snapshot</a> (believe me, I’ve learned the hard way on this one). <br> <br><b>“I haven’t change anything on the server for the last few weeks.”</b> <br> <br>Perhaps there are some updates to MySQL, Apache or to any number of their dependencies that you’ve missed out on. Try executing: <br><pre>sudo apt-get update && sudo apt-get -y upgrade && sudo apt-get -y dist-upgrade && sudo apt-get -y autoremove</pre> <br>to see if that solves the problem.