Dear you,
Forty is not a verdict. It is not a locked door. It is an age at which you already know something about what drains you, what matters, what you can survive and what you no longer want to pretend about.
Starting over now will not feel like starting at twenty. That is not a disadvantage. You are bringing information with you.
Let the next chapter be less about proving that you are not late and more about choosing what deserves the years ahead.