Ignoring details and personal feelings, if you are in a relation that is bad for you, you need to be able to walk away from it.

And if he is unwilling to communicate, you can tell him straight up that you aren't interested in spending your life with someone who cannot communicate. You only have one life.

If you are not willing to walk away when it is necessary, you have no leverage and no influence on the nature of the relationship.

Imo, you should tell your partner at the first moment you are dissatisfied that you are so she/he can change/adjust.
Some people stay in dissatisfied relationships. Others leave a dissatisfied relationships before helping their partner to do the right thing to improve the relationship.

That this has gone on for 20 years is bad. Either he knows and doesn't care. Or you never told him and he will have trouble understanding why suddenly his previously ok behavior is no longer ok. Difficult.