For anyone else having as much trouble as I did getting this to work…
First, you need to have the contents of your public key listed in a file called
~/.ssh/authorized_keys). I deleted the public key listed in the Settings>Security page of the DO dashboard. This allowed me to use my password when connecting to the server. Then I could edit the
authorized_keys file. You have to edit the file as the user that will being using that key - not as root.
Second, you need to make sure the corresponding private key is on your local machine and your local machine knows where it is. I’m using Windows and PuTTY so I add the private key to the PuTTY session AND make sure that Pageant.exe knows about it. (Google:Pageant add key).
TIP: When you make changes in PuTTY, like changing keys and such, if you don’t save the session it will not remember those changes when it opens again.
Hope this helps!