I'm afraid the main point(s) are being lost. For over a year I used "*k" to bring up the window where I put in "vnc://c-73-38-192-144.HSD1.ct.comcast.net/" and I could start screen sharing with her credentials.
Someone configured your router to port forward the VNC port to your Mac. That hole you poked in your router appears to have been closed, or Comcast changed the hostname of your external IP address. Since that address is from a Comcast domain, it is the external address Comcast assigned to your Modem. They may have changed that hostname.
You could use WhatsMyIp on the destination Mac to determine the external IP address and try to VNC using that. If it works, then your hostname has changed. If it doesn't work, then the hole you poked in your router/firewall is now closed.
And, now if anybody can figure out your new hostname or external IP address from the previous one you posted, they know you have an open hole in your router from which they can run VNC exploits to attempt to take over your Mac.