Ethernet switch

My house security cameras and all my hard wired internet lines run to my master closet where I had my own equipment set up with a ethernet switch to provide internet to all the hard wired locations in the home.

Xfinity has changed their policies on unlimited internet and require now we must use their equipment.

My problem is my new Xfinity modem Wi-Fi box does not allow me to use my ethernet switch.

What suggestions are there for me to fix this problem?

I only have internet with Xfinity. No cable, no home phone. Unlimited internet plan.