My point of view:
Your Subconscious Mind knows the amount of damage (material damage, trust damage, loss of integrity etc.) you have caused to her.
Her Subconscious Mind knows the amount of damage (material damage, trust damage, loss of integrity etc.) you have caused to her.
You cannot consciously lie to your own Subconscious Mind, neither can you to hers.
Consciously acting as if “everything is forgiven again” without BOTH Subconscious Minds agreeing to it is just delusional and lying to yourself.
Unless action is taken (this can be action on both sides or on one side), that will reconcile the created negative information in BOTH of your Subconscious Minds, there will always remain a negative effect stored and lurking in the background.
if your and her Subconscious Mind does not release this negativity, there will always be some hidden unconscious resentment lurking around in the background, and influencing the relationship negatively.
Confessing to her what you did is a good way to ask her and her Subconscious Mind for forgiveness.
When her Conscious AND Subconscious Minds have forgiven you, you have “burned off that karma”.
Or in other words:
Your conscious justifications to yourself mean nothing.
The truth that the Subconscious Minds are always seeing are everything.