So, first you have to define what your part in being deceived merits forgiving yourself.
I think, with some introspection, you will find that your assessment that being snowed, turning a blind eye, not recognizing, experiencing denial, trusting someone untrustworthy, amounts to being unable to solve an equation where not enough information was given. You had previous understandings that were false. You were attached to those understandings. You wanted to trust, feel cherished, special to this trusted person in ways that you thought precluded this kind of reality. In your misunderstandings, you believed you had this.
Now that you know otherwise, you are angry with yourself for not knowing otherwise, before you had the information to do that! In retrospect, things seemed obvious, etc. you go over it a thousand times, asking yourself why you didnt have the magical ability to see omniscient truth. There might be some anger towards yourself for ways in which you were a supportive and good partner. If you hadnt been so all in, this wouldnt be so unjust, right?
You could never have done that. You certainly cant go back. You are holding your previous self to an impossible standard. You are blaming the wrong individual for what happened to you.
That kind, loving soul whom you were was treated badly enough by someone else. Your previous self deserves to be loved and regarded with compassion, not heaped with notions of having failed for not recognizing being the only one acting in good faith. You deserve to be accepted by yourself for the good in your heart and the truth of being loveable, capable, and sufficient. your misused trust deserves to be mourned. It was a beautiful, silver prayer lived in earnest, and crushed by circumstance beyond your power to help.
Carry that dream in your heart with love for yourself for having had it. Its so sad that it was broken, because it was so beautiful that you had it.
That would be a pretty good foundation for acceptance. And if you process your feelings enough, forgiveness will come, as Asterisk said, in your time, in your way.
Accept and forgive yourself first. Forgiving the partner and the Ap can come later. When its right, you wont have to force it. Probably wont be possible without healing yourself first.
[This message edited by 5bluedrops at 1:36 PM, Saturday, December 27th]