Critical Illness cover is a good option in that situation, but more suited to paying for things like private treatment.
In the event you can’t work due to Illness or Injury, costs of everyday life/bills etc are best protected with Income Protection cover.
This covers ANY illness or injury, rather than a specific list of conditions like critical Illness cover.
This means things like Car/Bike accidents, mental health etc etc. Are covered.
They wouldn’t be with Critical illness.
Also Income Protection pays a monthly amount rather a lump sum, and can continue until you return to work, so no issues with making a lump sum last an unknown amount of time.