“That which is feared lessens by association.”
The ancients had a lot figured out.
If retirement is a frightful concept for whatever reason (loss, decline, lack of purpose) expose yourself.
Test the waters with a month off relaxing and opening to possibility. Pause and reflect. Consider the value of time, how much any of us have left (we can't know, that's the point), and luxuriate in the privilege of having yours to yourself.
Take Ovid's advice. Associate with freedom for a while. Once you get to know it, you might start to like it.
Then keep going.