abrodski,
oddz’s response is correct for your localhost - you just don’t need anything but self-installed certs on your text computer.
HOWEVER, I have to drop back because it seems as if you want to run your website off your own localhost and that has me worried (because you don’t have the expertise nor the ability to monitor your computer 24/7/365¼.
If you are on a VPS or dedi server, you can use your cPanel to create a self-signed cert (to chase potential paying visitors away) or update your old cert (with the CA - then install the updated code they’ll send to you). Since you claim to be a novice with system administration, I’d recommend that you have your host make those updates for you.
11 SSLs?!? Perhaps a wildcard cert might be worth considering as it should cover all your domains (and avoid the monthly charges for each dedicated IP address for each SSL).
My recommendation would be to think outside the box a bit, get recommendations from your host and from a CA that you trust, evaluate their information and go from there.
Regards,
DK