Changing history about an affair

I had an affair. No one found out-or shall I say it was never brought up or discussed w me w anyone in family. I got divorced. Clearly, there are rumors and my adult son is curious. I am stuck. i am still w this man-ithi k that telling the truth would do more harm tha. good and yet i am so tired of lying. This lie is 10 years old…So-This is one example of how I am cycling. Iwant the truth to be as listed below (option A) but I still have the other thought pattern (option b). I’m combining several models for ease.

Option A:
Circumstance: Adult child thinks i had an affair
Thought: I know that was wrong. I did the best i could at the time and that info is private.
Emotion: empathy, peace, and guilt
Result: Talk w him openly while keeping my privacy boundaries. and then…

C: have talk above
T: liar, liar pants on fire (jj-it’s way worse than that)
F: guilt ridden beyond anything i have ever felt
R: cry and then begin work again…back to option A

I think you will say I am doing the work-and I just want you to tell me it is ok to keep lying or to tell him the truth and i know you can’t…ugh.

Result: Honesty and integrity w kids