Wordpress giving error when I log in after trying emergency.php

I could not remember my username or password for my WordPress website. I tried using the emergency.php script.

I logged and I tried a few different possibilities for username, of which none worked. Now when I try log in to my website it just has 'error' instead of my site which was working perfectly.

How do I get my site back up and running and is it possible to create new log in details if all I have is the ftp details, thanks.