Q: have created a new password over and over but Apple, AOL, etc. will not accept any of them!

Please take these steps to resynchronize the iCloud keychain. Your keychain on iCloud and your other Apple devices won't be affected. Take Step 2 only if Step 1 doesn't solve the problem.

Step 1

Back up all data.

Open the iCloud preference pane and uncheck the Keychain box. You'll be prompted to delete the local iCloud keychain. Confirm—the data will remain on the servers. Then re-check the box. Follow one of the procedures described in this support article to set up iCloud Keychain on an additional device. Test.

Step 2

If you still have problems, uncheck the Keychain box again and continue.

Triple-click the line below on this page to select it, then copy the text to the Clipboard by pressing the key combination  command-C:

~/Library/Keychains

In the Finder, select

          Go ▹ Go to Folder...

from the menu bar and paste into the box that opens by pressing command-V. You may not see what you pasted because a line break is included. Press return.

A folder named "Keychains" should open. Inside it is a subfolder with a long name similar to (but not the same as) this:

           421DE5CA-D745-3AC1-91B0-CE5FC0ABA128

The above is only an example; yours will have a different name of the same general form. Drag the subfolder (not the Keychains folder) to the Trash and empty.

Restart the computer and re-enable iCloud Keychain.

Does your old password still work? Are you changing your password in your email client for example without also changing it in your email server?