Changed General Settings URL Now I Cannot Log In

See Changing_The_Site_URL.

Got access to it again, thanks!

I ran into another problem after fixing the login issue. All of my pages and links now have an error:
Not Found
The requested URL /index.php was not found on this server.

I edited my config.php to include:
define(‘WP_HOME’,’https://example.com’);
define(‘WP_SITEURL’,’https://example.com’);

My index.php file is still where it is, so I don’t know whats causing the problem.

Change the urls back to https://example.com/wp

In the general settings? They are back to https://example.com/wp. (they are in a gray box and are locked, because of the define statements maybe? what else could be the problem?

No – via one of the methods outlined in Changing_The_Site_URL.

I used the first method from that link and changed the urls back to example.com/wp, so now the homepage works fine, but the linked pages and any new page created comes up with an error message. Not Found The requested URL /index.php was not found on this server.

Try resetting your custom permalinks back to the default setting via Settings -> Permalinks. If this works, then review Using_Permalinks before setting a custom permalink structure back up again.

I think that the victims of this issue are growing, and it is likely that it soon becomes epidemic, simply because bloggers are not, necessarily, IT-educated. It will become much more comfortable to the blogger if he is provided with a straight-forward tool to reach his Settings page and restore it to the state preceding the introduced changes. The technical procedures presented on this platform are for professionals, not for ordinary bloggers who may be highly educated, but not on this subject of programming and the need to delve into the root directory.
For not-qualified bloggers, facing this problem, the best may be to start afresh: Register with wordpress, using your username and password. Then transfer your blogs to your new platform, and forget about the old platform.

It will become much more comfortable to the blogger if he is provided with a straight-forward tool to reach his Settings page and restore it to the state preceding the introduced changes.

Short answer: People really shouldn’t be changing anything in the Setting page unless they understand what exactly what they are doing. That’s a bit like trying to re-plumb your car engine without knowing anything about how the internal combustion engine works and then complaining because the car no longer works.

If you don’t know what a setting does, don’t change it without checking first.

As for the solutions offered, at least two of them only need some knowledge of FTP – and frankly that’s a skill that any site owner should know.