Please try accessing your droplet using the web console in the control panel. Click on the droplet then select access and open the console.
If your droplet is inaccessible via ssh there are a couple likely possibilities.
1.) Your droplet failed to fully boot back up. If this is the case, please open a ticket. Our team can mount a recovery ISO image which will allow you to run a filesystem check and repair through the console. They can walk you through the process.
2.) Your droplet booted but networking was unable to be started. In this case you would again want to open a ticket so our team can take a closer look and assist you in resolving the issue.
You can open a ticket with our team either through the control panel or by emailing firstname.lastname@example.org from the email address on your account.