Ordinary language is all right.
One could divide humanity into two classes:
those who master a metaphor, and those who hold by a formula.
Those with a bent for both are too few, they do not comprise a class.
Those to whom one confesses and those to whom one apologizes.
We confess guilt to those we have wronged; and to others who may hardly know us. (This is one way confession can be hard; as if we are introducing ourselves as bad people.)
To confess shame we may need those who know us best; we need not have wronged them, nor even to have done anything they would fault us for.
What's between us is sometimes what we let pass; and sometimes what we refuse to let pass, if only between us.
The world can make you keep something secret, but not something private.
So if you need secrecy to be yourself, does that mean you're a bad person? Not necessarily; it could just be that others have made you feel like one.
You can be yourself in private; but not in secret.
Anyone who says glibly, 'just don't have anything to hide!', acts as if it makes no difference to be made to treat your privacies like secrets.
Secrets are kept deliberately; so preserving anything private as such can seem like keeping a secret.
What is between us is often private but not secret.