Home Network Setup

Our house is a long house. And I need to get my network from one end to the other. Currently, I have it coming in to our family room on the southern most part of the house. I attempted to move it into the middle so it would reach the whole house, but it seems that the two (yes, two, they are a total of 10 feet apart) coax options in the living room do not connect for some reason.

So, I’ve tried turning my AirPort Extreme into a repeater, but it keeps telling me that my network cannot be extended. I’ve got some modem/router from Verizon that I “have to use” for the FiOS, and I’m not wanting to buy anymore gear. What would you do?