computer thinks my location is somewhere where it is not

Hey there peaches2165. Have you already cleared cookies and cache on your device?

You likely recently received a new / different WAN (public) IP address assignment to your connection from their DHCP server / IP address pool, and the rDNS / geolocation data that is associated with it is now incorrect for you as it previously belonged to someone else who lived in that other area. 

Comcast shuffles blocks of IP addresses around the country all the time. And after doing local plant maintenance / upgrades. ISP's don't correct this. A third-party service does. Unfortunately, this is typically a back-burner thing to get corrected. The only thing that you can do is to report it. You can try this;

https://www.maxmind.com/en/geoip-location-correction 

https://support.google.com/websearch/contact/ip/ 

https://ipinfo.io/corrections 

https://www.whatismyip.com/ip-address-geolocation-incorrect/ 

https://ipregistry.co/data-corrections 

Wait for the geolocation provider to approve your request. If your request is approved, the amount of time it takes to see the correction varies by provider. The average is two weeks to a month or more.

You can also try this;

If you are using a router that has a MAC address cloning feature, you can clone a different MAC address into it. This will force a change of your Comcast-assigned WAN / public IP address. No guarantees that the new address won't also have incorrect geo-data as it may be from the same block of IP's. YMMV.

And you could also try using a VPN service, but it's a crapshoot on what IP / endpoint geolocation will be presented to their servers.

Official article: https://www.xfinity.com/support/articles/correct-geolocation-data