Sounds like you have a cable that isn't to specification?

Personally, I don't bother putting that nut on, instead, I flick the spring off of the clutch pedal & let the weight of the clutch pedal hold the cable in place. This makes the spring on the clutch fork mandatory but the end result is a clutch that feels better because the free play is much less & more consistent. Only downside is that your clutch pedal won't be pulled up against it's stop which means it won't be level with the brake pedal(if that actually matters).