Now I keep losing the routers internet connection to the computer.
Actually it sounds like the router's connection to the Internet that's to blame. The internal connection between the router and your computer should be the same as before -- and that was working. You can always ping the router from your computer to test that connection.
Like Draclvr said, it's probably Comcast that has to fix it. Any problems in the cabling between your router and the Internet are their responsibility.
If you haven't done so already, turn off the router for a few minutes and then turn it back on.
I don't know if you have fiber, but if there are any stretches of cable between you and Comcast that use older copper cable, they may not be capable of supporting a higher Internet speed and may have to be replaced.