I can't connect to the internet with a static IP

I host a website on a little server in my room, and I recently upgraded my router. In order to make my server accessible via the domain name, I need a static IP for both the server and the router itself. I got a static server IP no problem, but when I change the router itself to use a static IP to the broader internet, I lose all internet connectivity.

I'm just using the default static IP automatically given to me by my ISP, so I don't see how the configuration change could be screwing anything up. Any info on this would be massively appreciated.