Hi kteddiey—I would be willing to help you–but you will have to give me a little more info.
What is the URL of your site?
Did your letencrypt installation complete (did it seem successful)?
Can you access your libretime gui via https?
Did you check to make sure that there is a concatenated (key+cert) pem file in the location you configured in icecast.xml?
Did you open your firewall to the secure port configured for https in icecast.xml? I tend to use 8443 or something which does not conflict with browser use—I would not use 443.
If you tell us your domain/url I think we can get to the bottom of it.