The task you do well may need a second trained person more than it needs your permanent presence.

Being the person who does something well is satisfying, and it slowly makes you the only route to a thing other people need. That works until you are ill, away, or simply tired, at which point your competence has become a single point of failure. What the work needs from you eventually is not more presence but another person who can do it.

Pick the task only you handle and teach someone else this month, in whatever order they can absorb it. Write down the parts that live in your head. Let them do it imperfectly once while you are still there.