Does divorce occur by saying "I divorced her twenty years ago" to an imaginary person, knowing that the marriage took place only two years ago, and does repeating the phrase to ensure it is uttered aloud affect the occurrence of divorce?

What you mentioned is a whisper [from Satan] that must be ignored. Your wife remains under your marital bond, because what occurred from you was self-talk and whispers. Doubt in uttering the divorce does not remove the certainty of the marital bond's continuation. The marital bond should not be a field for your whispers and illusions. If you resolve to divorce, then have two men witness it, so they hear it explicitly from you.