How would I go about fixing my Internet connection?

Same problem here and for me it has been line sharing.  IE, I removed the high end splitter I bought and just ran a line to the modem.  For some reason the line is losing signal when I share it with my TV tuner.

I did some research and this has to do with signal loss / weak signal coming into the house.

Cox should be the one responsible for any weak signals.

For starters it might help to know what the modem status looks like.  You can access that by opening up http://192.168.100.1 in your web browser.  If you could post that infomration here it would be helpful in understanding where the problem may be.