My Dad dragged our cable two weeks ago and he was about 70 miles away from any type of trailer place. Luckily everyone was going out there to see them that weekeknd since it was Father's Day. I went to the local RV place and they sell two lenghts of cable. One is 8' for $36 and the other was 10' for about $52 and I got the 10' The cable itself has the plug on one end and the other end it just a bunch of color coded wires.
Our cable didn't terminate into an electrical box. Out cable went through the floor of the camper and into the front storage area of our dinette. Everything was just connected with wire nuts.
This is what it looked like when we got there.
And then this is what the wiring looked like in the dinette seat.
The cabel was simply feed through a hole in the floor and it was held in place with a glob of caulk or something. The hole was not completely plugged. My brother went below the camper and I was in it and we would take turns tugging a bit on the cable to free it from the caulk. It was difficult to do. All of the wiring was color coded so it was a breeze to fix.
I would suggest buying a new cable and replacing the one you have now. Then roll up the damaged cable and keep it somewhere in the camper. If you end up damaging the new cord then you can use the wires from the old cable and splice them together. For what it's worth, if you look on the cable you will see the wire gauges used. I think it' ssomething like 1 10 gauge, 2 12 gauge and 4 14 gauge. Something along those lines.