Hi there are a couple of ways …. Move wire 8 from rj45 and use that as 1 (both ends) but you might loose ir
Or you could buy a tp-link Ethernet over power and not use the damaged cat cable at all
as far as finding the break ….. it is usually at the rj45 ends ….. but worth looking along cable run paying attention to cable clips that might of been too tight or areas were it bends around corners but if it has worked in the past it is unlikely to be a cable break …. Usually it’s the power cable side of the rj45 that gives the problem
i would look at cable run and see if it has any loose runs ….. we’re the cable could be moving with wind or under stress from dropping down
can you power the camera locally if needed
https://www.tp-link.com/uk/home-networking/powerline/tl-pa717-kit/