Need help w/setup of personal router

I had to reset my router yesterday afternoon and then my service had a slight interruption - fast forward to this morning when my modem was chronically offline despite multiple resets (via 1-800-XFINITY as well). I had already done a remote refresh, and was still offline so was given the option to reset the gateway which I accepted. Now my router for some reason WILL. NOT. CONNECT. despite being plugged into all the places it has always been (the wall and the modem). I use an ARRIS modem and a NetGear router. How can I fix this? The internet is fine now as long as its wired into whatever needs a connection with the LAN cable. I have the LAN going from the modem to my PlayStation4 right now and the internet is clearly fine now. The problem is the refreshed gateway and factory reset router. Please help!!! I cannot wait until an appointment on Friday. We have multiple people in the house with college essays and assignments that are now overdue!!