there's a metal clip that holds the cable end on (it slots over the rubber).. but i would also say you'll need a new cable as the auto adjuster will now be ruined!!
It's also possible the clutch arm ratchet has gone so make sure you can feel the tension on the arm and if its slack you'll need these pieces (for sale if needed

).. thisis what happend to mine and luckily a specialist told me the ratchet is quite common (after a few garages told me the box had gone!)