Yesterday, I posted this thread which was subsequently locked for being too localized. I think this is much more searchable (and I still need help!) but I'm sorry for the bad thread.
Like mentioned in that thread, I changed different files in the comments module folder and added columns to the database table. This sort of disabled comments, both the settings in page content settings and their appearance on the page normally.
I tried to fix this by: uploading a completely new 'comments' folder (I have a back up if that was a bad idea) from a new copy of the core, and deleted those table fields. Still no sign of fixing any of the problems I created.
How do I return the comments to their normal setting so I can approach the altering I was planning on doing the right way this time?