I have experienced all of the above, loose adjustment bolt, frayed cable and a broken diaphragm plate. And I was still driving the car until I pulled it apart. The diaphragm plate was accompanied by two of the three clutch torque spring/bolts also being broken.
All of them are simple to replace/fix.
You will have to look closely to find that the torque springs are broken as each one has two spring leafs and maybe only one is broken, it will need to be changed.
Bill