500 Internal Error after changing address

Using 2.7 but not 2.7.1: I was trying to change my address from smuffle.ohpanic.info/wp to just smuffle.ohpanic.info but then I kept getting redirected to another white page with this Internal 500 error message when i was clicking Save if I remember correctly. So now I’m trying to comment on my blog post by clicking the number of comments to load the comment page and some of my visitors say it just reloads the page but for me, it gives me:

The server encountered an internal error or misconfiguration and was unable to complete your request.

Please contact the server administrator, webmaster@smuffle.ohpanic.info and inform them of the time the error occurred, and anything you might have done that may have caused the error.

More information about this error may be available in the server error log.

Additionally, a 500 Internal Server Error error was encountered while trying to use an ErrorDocument to handle the request.

please help 🙁