I have already deauthorized 2 of my PCs earlier today and they do not show up in the list; however, the error message indicates I cannot authorize my new laptop because I already have 5 PCs authorized?? WTF??

Try "Deauthorize All" and then reauthorize any you still have and want to use. See the following from Authorize or deauthorize your computer for iTunes Store purchases - Apple Support

To deauthorize a computer that you don't have access to, you have to deauthorize all of your computers. Then authorize each computer that you have again. You can deauthorize all computers only once a year.

1. Open iTunes.
2. Choose Account > View My Account.
3. Sign in with your Apple ID and password. Forgot your Apple ID?
4. At the top of your Account Information page, go to the Apple ID Summary section.
5. Next to Computer Authorizations, click Deauthorize All.
6. Authorize each computer that you use again.