IDK ... I see some similarities with my experience that may or may not be there.
My W did not decide to confess after a sleepless night. After a sleepless night she did decide to end her A and stop lying, so when I asked a question that morning, she confessed.
The timeline is detailed, supported by phone histories, messages, internet activity, ring doorbell, etc. She has told me things I never could have found out which do not paint her in a good light.
My W never did a TL; we put one together ...um... together. But I took answering questions honestly as a sign that we could R, and showing herself in a bad light was a key indicator of honesty to me.
I interrogated my W day after day for months. I asked the same questions repeatedly. I sought essentially the same info with questions I posed from varying points of view in varying ways. I kept looking for inconsistencies and found none. Eventually (maybe 60-90 days) I decided I had the truth. I didn't have everything, because that's impossible, but I decided that my W was not hiding anything and that there were no deal killers hiding in unasked questions.
BTW, at about a year out, I thought I heard some major, deal-killing TT, but W pointed to the TL and showed me where it had been documented. The fact just struck me differently in 2012 than it did in 2011.
So I recommend that you keep asking questions, comparing answers, and tracking down inconsistencies.
I'm not implying that your W is lying; in fact, from what you say, she's come clean. As Bigger wrote, it's critical that you decide/realize you have the truth.
The truth is critical to R, but before R, you have to heal. You have to process a good deal of the vast amount of anger, grief, fear, and shame that comes from being betrayed out of your body.
You can do that by looking inside and figuring out what you really want. You've got to feel the feelings and let them flow out of your body. Stuffing your feelings will hurt worse than feeling them now. A good IC can help.
One exercise I found useful was to imagine a good life after D and after R and after temporizing, etc. IOW, I opened myself up to as many options as I could imagine. That allowed me to choose between good options rather than seeing myself having to choose the least bad option.
Don't stay if you want D. Don't stay unless you believe your W will do the work necessary for R.
My reco is not to think so much about D vs R right now. Instead, think about your healing first and your wants second.. Don't think so much about what she did to you - she has no excuse, and there's nothing good about cheating. Think about what you need to know. Think about what you'd require from her that would make you want R.
If your W is one of your wants, then observe her to see if she'll do the work necessary to R.
Being betrayed feels awful, and the feeling will last a lot longer than you think it should, but you can survive and thrive.