Every SIer has a profile. Every profile includes a link to recent posts by the member. Some of the profiles include a lot of info in addition to the link; some don't. In evaluating posts, looking at a profile and recent posts can help a reader understand the mindset of a poster.
You could spend the next five years of your life undergoing excruciating couples therapy, dissecting every text message, installing tracker apps on her phone, and analysing the exact tone of voice she uses when she says she is running late from the office.
This is an image of R that bears little resemblance to reality.
Among other things, if a person in R has questions about what their partner thinks, does, or says, they bring up the issue and get it resolved. R requires addressing issues, all of them. R requires both partners to be active, not passive. R requires both partners to be ready to split if they hit an unresolvable issue.
If R is or becomes misery for a couple, the best thing to do is for the couple to meet and decide to change what they're doing - that is, stop the misery 1) by doing the work necessary for R or 2) by switching to D.
People who successfully R take responsibility for themselves, figure out what they want (D, R, or take time to gather more info), rebuild themselves, almost always through IC, consciously build a new M that serves both partners ... in short by commitment, honesty, work, daily ( sometimes more than daily) recommitment to one's partner, to keep working, and to one's M.
Read the Positive Reconciliation Stories, a thread that's pinned at the top of this page. That thread is from people who have had successes in R. The posts provide some indicators that you can apply to yourself and your WS - lots of similarities probably means R may be a good choice for you and your WS, lots of differences probably means R is not for you.
The SI rule of thumb is 2-5 years to recover. That may look daunting, but remember: most of us start feeling a bit better 6-12 months from the last hurt (new information can set a BS's healing back). Then there's a slow rebuild of the ability to feel joy.
If you don't start feeling better over time, you probably need to change what you're doing.
*****
HurtingDreamer, some of what you write says R is possible; some says R may not be very likely. More info may help us provide guidance one way or another.
You'll find 2 types of guidance on SI. The first aims to help you decide what you want and figure out what's possible for you. The second tells you what to do. My reco is to rely more on the 1st type than the 2nd.
If both you and your W want to build a new M and if you both do the necessary work and if both of you are willing to be patient, R is possible. Not easy. Not guaranteed. Possible.
IMO, my reco is to dig deep inside and stay away from R unless you really think you want to spend the rest of your life with your W. You may not, and if that's the case, you can save yourself time and effort by choosing D now.
If you think you might want to R, look at your WS.
Has/will she become honest?
Does/will she answer your questions fully, or do you think she holds back the full story?
Does/will she take responsibility for her A or does she blame you for it?
Has/will she stopped minimizing?
Will she do the work necessary to change from cheater to good partner?
Does she want to R?
If she won't commit fully to R, my reco is to put aside your own desire. R takes 2. You can't do it yourself.
*****
You're at a stage that is bad for all of us. It gets worse for some of us as the reality of being betrayed sets in. You have to navigate this period one way or another. You have a basic choice between stuffing your anger, grief, fear, shame, etc. and feeling it.
If you stuff your feelings, you're at risk of the pain festering and coming out years or decades from now. But there are safe and unsafe ways to feel the pain. A good IC can help you learn how to process thoughts and feelings safely.
IMO, we have to process the pain that comes with being betrayed no matter what we choose to do with the shattered relationship. Neither R nor D mitigates the pain of being betrayed.
*****
Keep in mind that your W has failed. You haven't. The A came out of her issues with herself, not from issues with your or your M.
Also, above all, have faith in yourself to heal. You've got the power you need.