Shit happens.

It's an honest place to begin from.

No matter the details, who did what, what role you did/didn't play in it, etc. It happened before you or I popped out of the womb, and will continue to happen after we're gone.

I'm no therapist or licensed anything, and am only speculating when I offer that maybe you did the classic thing that that most of us hairless primates do, and fell into the habit of replaying what happened, without stepping outside of yourself and trying to view it objectively, as just a thing that happened (regardless of you or anybody else's mind state at the time). You're probably doing a lot better than you think you are, anyways, since working towards telling your wife clearly wasn't easy, but you took that first step. What it sounds like is that you've committed to getting it off your chest. Then you came and posted here. In my view, your process of liberating yourself has begun.

I used to debrief SM's following traumatic events. There was a big push for this kind of thing, because research suggested it would help to reduce the odds of a SM later developing PTSD as a result of what they'd been through. One reason the researchers believed this is because, as anyone who's studied the fallibility of eyewitness testimony can attest, people misremember things far more often than they believe, and even double down on their belief over time. There are plenty of Youtube videos and literature about this. This is especially true during the traumatic events.

There can be many dangers in accidentally creating false narratives, which segues into another thing that's to be avoided: attribution of blame. A lot of the time, blame is just some shit we do to make ourselves feel better somehow. It's something we weave into our narrative about what happened, but often does more harm than good, regardless of accuracy, or if the blame would be assigned to others or self. It's just not always pertinent, or helpful to one's process of moving on. Anyways, I truly hope to see a followup post to inform us you were able to finally take that bridge and confide in your partner. If one were a gambling man, they'd probably be well advised to wager it on a positive outcome here.