No reason to call comcast, don't freak out, you can fix this yourself.
Go into your xfinity panel, login to the Technician panel, and re-setup the panel. (its under one of the settings)
Code to get in is counting down like a Spaceship takeoff after the number 5. (4 digits) Anything can be entered on the 2nd login page.
Follow those instructions on setting up the router again, and it will setup the security router again. NEVER HOLD RESET ON THE XFINITY HOME SECURITY ROUTER. EVER. Just power cycle it if it's acting up.