I see that you have added your login credentials publicly, so I have moved it into a secure note. However, I would suggest you to change your password immediately as a safety precaution.
When testing your original issue, I see that you're getting an error
500 internal server error when editing your homepage (see secure note). Usually it could be related to a PHP fatal error, which you need to investigate it further by enabling your WP_DEBUG mode (https://codex.wordpress.org/WP_DEBUG). Once you enable WP_DEBUG mode, you should see appropriate PHP error messages once you edit your page.
Or else, enable your error log by following this resource (https://snapcreek.com/blog/wordpress-error-log-friend/) and then when you try to edit your post, it will record any PHP errors in your error log.
If you're still having issues, we will require your FTP credentials as well to investigate your issue further. Make sure to submit those information in a secure note.
Let us know how it goes.