Locked out of my website

I’m not able to make any changes to my WP site, even though I seem to be able to log in.

I’m confused and think I might have been hacked. Today I got a message from https://wpbusinessnetwork.com/mod-security-error/rule-13051.html that says:

“We apologize for the inconvenience! You are seeing this message because your site has recently been targeted by attackers attempting to gain access to your WordPress Dashboard. In order to protect your site your WordPress Login page has been temporarily disabled.

Unfortunately, you will be unable to login to the Dashboard until the block expires.

How to get help

For more information on:

Why this block was enacted
How to further protect yourself
How to regain access
Please visit our support site.”

The support site is a link to “https://www.inmotionhosting.com/support/news/general/wp-login-brute-force-attack” but most that page doesn’t load properly and half of the links show only partially on the left side of that page.

Does this sound familiar to anyone? Can you tell me what’s going on? It doesn’t make sense that WordPress would take over my site and lock me out. Also, I don’t believe that that is an official WordPress site. I think it’s a private party who owns it, so that really makes me suspicious.

Unfortunately, I’ve tried backing up the site unsuccessfully. There are some questions in the setup area that I just didn’t know how to answer, so it isn’t backing up.