I think at least one IC session is a great idea. The sooner the better.
You also need to develop a plan in case something like that happens again. What if you catch her with OM again in a week? You would probably be even more angry. Maybe some vets can give some ideas for a plan in that sitch, but I think you should be prepared to LEAVE immediately if you saw her with OM, OM2 or whomever. You should obviously continue to pursue detachment until she is fully committed to reconciliation, but no matter how detached you get, you are at risk for an outburst if you saw her with OM. I am by no means an expert, so I would defer to the vets or especially an IC for strategies to prepare and handle that.
Also, could you go into further detail why you can't go dark, especially if she restarts with OM, or starts with OM2? After this episode, I don't think trying to live under the same roof should be considered for a second longer if she started another A. There are solutions to any reasons that hold you back from that, and none of them have to involve filing for D if you're not ready to drop the rope.
dawgy, you've made a huge step to acknowledge that you're wrong. Have you reconsidered an apology? An apology doesn't have to validate their horrible, selfish A. It also doesn't have to apologize from blowing up the disgusting A. If nothing else, I would apologize for exposing your S to that.
And don't get too discouraged. As long as it doesn't become a sustained behavior, the damage can be limited.
Me 38, WAW 30 D11 (former marriage) S2 T 8 years M 3 years BD 8/20/23 S 8/20/23