si, most of us really beat ourselves up with trying to figure out if our W is having an A, how bad it is, how often, is it physical, etc. etc. The best thing I ever did for my own welfare and recovery was assume the worst, and then let it go. I mean here's the thing, you've been fired as H and if she's not already sleeping with someone else then she is consumed with the idea of it. She doesn't like you and may even hate you. She might find you repulsive right now. Yes it's that bad, the scenario is literally the worst thing you can dream up. So how do you change her mind? YOU CAN'T, SO DON'T TRY. That is how she feels right now, and probably will for a long time to come. In her mind if she sleeps with someone it is A) none of your business and B) not an affair. Wait what? Yes that's right, she no longer considers herself married except on some bothersome piece of paper in a filing cabinet somewhere. So (in her mind) sex with someone else isn't an "affair", it's just her moving on. There's a "rationalization hamster" running full speed in her head and no matter what you say or do it will spin away.
So you leave her to it. You get out. You GAL. You quit concerning yourself with who she's going out with, texting, emailing, thinking about. You get about the business of making yourself a manly man again, one that realizes he has far more value than to let some lying cheater tie him behind her car and drag him around on the ground.
You do that while at the same time she's exploring her GGW life. Somewhere down the road, she realizes GGW is a moral and emotional dead end. And she looks back. She should see a strong, stable, solid hunk of a man who no longer cares if she is looking or not. THAT is what may attract her back. And if it doesn't, you will have moved on anyway.
The thing about DB'ing is it makes you whole again. Whether you reconcile or not, you win. You will be better, stronger, healthier, more confident. You'll get there, just be patient.