I am very glad to report that my issue was fixed last night. I had opened a support ticket with my hosting server, Bluehost.
They said that my issue was connected with the WordPress core files, which they replaced. I am now able to log into my account again, and everything is back to being functional.
By the way, now I also can’t even log into my backend anymore. Yesterday, that was still possible, although once logged in, all I saw was a white, “empty” screen.
Hey Kookidooki,
Thanks so much for the link to the video – I must not have done something right though. It’s still not working. Ugh.