Bill

Good deal. Carry on. 🙂

It’s quite common to have bots (or humans) scouring the web for plugins with known vulnerabilities, or for unprotected core directories and files. Keep your WP installation, plugins, and theme(s) updated, and dump plugins and/or themes that aren’t being kept updated.

I would recommend (if you aren’t already using one) installing one of the top-rated security plugins for some added protection.

Also, go over this page for some things you can do to protect your site.

I don’t see why the theme name should be so prominent on your site. It’s confusing for a visitor. Usually it isn’t even visible except for maybe a mention in the footer. Are you sure you can’t replace that with your site title, maybe in Appearance > Customize?

There’s no way to set up an actual page to bring me back to my posts?

That would be the function of the menu item, present on every page that has the nav menu. So in your case, set your landing page to be ‘recent posts’. In Appearance > Menus, remove ‘/home’ from the home menu item link. Then that menu item should take you to your recent posts.

I’m really sorry you’re having to deal with this. You should start by going carefully through this page to learn about what to look for and the steps you need to take to set things right again. I’m afraid there isn’t really an easy way. Good luck!
http://codex.wordpress.org/FAQ_My_site_was_hacked

Clicking on your site title (above the menu items) returns you to the recent-posts page. You can add a link to your menu specifically for that posts page if you like. Use this page to help:
https://codex.wordpress.org/WordPress_Menu_User_Guide

Your question is not very clear. If you mean that the changes you make to a page are not showing up, make sure you clear your browser cache, as well as the cache of any caching plugin you might be using. Also you can try another browser as a test.

Try resetting your permalinks in Settings > Permalinks. Sometimes that will clear up sudden 404s.

what and where is the mystery ‘Admin Panel menu’?

Sorry to say, but this is part of the site admin backend which you access by logging in. 🙁

if I go into my WP.com account, I can disable various plug-ins

If you have previously enabled Remote Management, I believe that may be something to try. If you haven’t, I don’t think you’ll be able to without being able to log in, though I’m not sure since I don’t use that.

However, disabling plugins and your current theme is a good thing to try at this point, so we can do it another way if Remote Management (from WP.com) isn’t an option. If you’d rather not, just ask your web host to do it for you on one site as a test. Simple for them. (You might ask them about the login problem first, even before that.)

To try it yourself, log in to your hosting account cPanel and use the File Manager.

Navigate to the folder of the site you want to try it on and find wp-contents/themes/activetheme (e.g. divi) and rename the active theme’s folder to ‘activetheme-hold’ (e.g. divi-hold).

Navigate to wp-content/plugins and rename the plugins folder ‘plugins-hold’.

That will disable the theme and plugins and cause WP to use a default theme. Go back and clear your browser cache and cookies and try again to login. Try both your new password and the old (clearing again in between). If nothing changes, you can go back and rename the two folders to their original names.

Before you make changes, it’s always good to make backups of your site and database, which you can do using the backup tools in cPanel. Let me know if this is unclear.