Hello my friend. I'm sorry you find yourself a part of this club that nobody wants to join.
There is a sort of standard set of advice points often given to newly minted BH's who appear here. I'll get to some of them, and let other posters add to the list. But let me address one point first, out of order. Your WW didn't fuck another man because she thought you had or were having an affair. Have you heard the word "backronym"? That's a linguistic slang term that describes people creating acronyms in a false effort to explain the roots of a slang word, such as a curse word. "For Unlawful Carnal Knowledge" is possibly the most famous. The word "fuck" has been in use in the English (and related) language(s) for centuries, evolving from Middle English, Old English, and Germanic predecessor variants. In fact, other than WWII-era military coinage (i.e. "Fubar"), almost no slang ever evolves from an acronym. The "backronym" of "For Unlawful Carnal Knowledge" is completely false, a bit of adolescent humor with zero roots in reality.
Similar with your WW's explanation of why she decided to arrogate the right to decide that her half of your marriage would be a secret, one-sided open marriage. That the part of her vows where she made a solemn promise in front of God and family to foresake all others until death, she had her fingers crossed secretly behind her back when she looked you in the eye at the altar and made that promise to you.
The reality is that she did it because she wanted to. She wanted to feel another man's dick inside of her, and therefore she actively sought this out and went for it, only stopping because she was caught. Now, she's inventing a "backronym" explanation in an effort to bully and browbeat you into swallowing your pride and shutting TFU, which sounds, based on your post, as if it's working.
It won't work for long, my friend. I would suggest you spend some time reading other threads here. You'll find that what you are doing right now is a classic case of rug sweeping. That never ends well. The anger and the bile from being cheated is sitting in your gut, rotting you away from the inside, Exhibit A being the fact that a year later, in the middle of the night, you found this place, created an account, and posted what I hear as a cri du coeur in the wilderness, seeking input from others who have been through the crucible of infidelity.
First things first. A year after DDay, that's just a flash in the pan in terms of your healing. Even if you left her and met somebody wonderful and kind and healing, it could be years. However, white knuckling it and forcing yourself to remain in a broken marriage with an unrepentant cheating wife who, I gather, has done zero work to help heal the trauma, that, my friend, is your own private Hell. To be clear, you are choosing it, but it's Hell nonetheless.
Typical advice for men in the wake of Dday: hydrate, exercise as much as you can, lay off the booze. Take care of yourself. Get yourself tested for STD's and require your WW to do the same. Tell the OBW you're doing so and ask her to confirm that the AP has done this and has gotten negative results.
In the meantime, spend some time pondering this koan. You say:
To be honest, I'm not sure why I stayed. I did, do and will always love my wife, and my kids are my everything. I love my life and what we built. However, the anger is still there and the facts of it all don't go away.
Consider what you know about your WW. Specifically, you know that she is the kind of person who will secretly decide that she wants sex with another man outside of the marriage, so she will seek this out and pursue it, all while lying to you and deceiving you. To carry on a LTA of this nature, she must have invested a ton of energy and imagination. She must have told you hundreds of individual lies about where she was going and what she was doing.
If you were a single man, dating her, and you learned that she had done this to a prior boyfriend, you'd be concerned. You would have learned something about her character as a human: that she is disloyal, deceitful, and dishonest, on a whim. When it suits her. Marriage with parenthood is a giant undertaking and responsibility. Would you go to war with a companion soldier who had those personality traits? Why on earth would you choose to be married to that? Exhibit A: she doesn't want her friends or anybody to know the truth about her personality and her choices. She is still actively lying to the world about who she is and what she does to those who trust and rely on her. Holding out a false front. Why would you enable that?
More to the point: why didn't your WW choose to invest that same level and degree of time, energy, and imagination into fixing your marriage and spicing up your sex life? You say, "based on our lack of sex". I take it that your marital sex life was in a low. This is common for married people with children. Sexual activity ebbs and flows over the years. Committed spouses who are concerned about this take action and invest energy into revitalizing their marriage. Fixing it. Not cheating.
You should buy and read the book "How to Help Your Spouse Heal from Your Affair" by Linda MacDonald. It's considered sort of the Bible of affair healing here on SI (and most other infidelity forums). The book is written for wayward spouses, but it's useful for BH's as well. If your WW has even an ounce of concern for your marriage, she will read it and do everything it suggests.
Which leads me to another point. What your post does not discuss, at all, is the work that your WW has been doing to heal this. I'll assume for now that this omission is because your WW is in fact not doing any work to fix this. Rather, she's browbeating you to rug-sweep it. That is the worst possible response, both by the WW and the BH. It means, as a practical matter, that although she may not currently be fucking Mr. Goodbar, the affair is essentially still alive within your marriage.
Cheating 101: the cheating, lying spouse has a character flaw, one that leads her to lie to her husband and seek out another man's dick rather than try to honor her vows and improve her marriage. Your marriage simply cannot work unless she fixes that flaw. She needs IC. She needs to figure out what is broken in her moral compass and repair it, make herself into a trustworthy person (which she is not at present). After she does that, you then decide whether you wise to be married to that new person. For now, at present, you aren't married in any spiritual way, at all.
Stay away from MC (marital counseling) unless and until she does this. It's a waste of time. Worse, most MC's are charlatans who know nothing about the trauma of infidelity. Most of them push an agenda of rug-sweeping and blame-shifting.
Finally, expose. Cockroaches scatter when the lights come on. Why would you enable your WW to continue lying to the world about the actual person she really is? At least find a couple of trusted friends and tell them. And her parents ought to know as well.
My personal advice to you. You say you were married about 17.5 years when she started her 6-month affair. That means married about 18 years on your Dday, which was about a year ago. Nearly 20 years. If you guys married between about ages 25-30, which is common, that puts you south of age 50 today. I reckon your kids are in their teens.
As an aside, a wife cheating when kids reach the teens, that's utterly cliche. As the kids mature and no longer need the "little kid" type of mothering, and as middle age advances, some women experience an existential crisis over notions of losing their youth, etc. Most functional adults realize this is a normal passage of life for everybody and they invest in their marriage, knowing that is the ship that will take them into old age. People with messed up value systems seek out other sexual partners in a pathetic and desperate attempt to reclaim fading youth, find excitement that they fear is waning. I reckon your WW's affair is a cheap and tawdry and cliche as most are. In that way, she's not even a little bit special. Rather pathetic in fact. Bottom line, a woman of a certain age who confirms that, in her core, she's a disloyal individual, a liar and a cheater.
Meantime, there is you. The trauma a man feels from a WW's sexual infidelity is real. Feelings of sexual humiliation and emasculation, etc. You haven't mentioned whether you and your WW had a period of HB, so I'll assume you didn't. Even if she does all the work, exposes herself to her public, fixes her broken moral compass, etc., even then, sometimes the trauma felt by a man when a wife enthusiastically jumps on another man's dick and returns over and over for it, sometimes that trauma is just too much to allow the marriage to function. There's no shame in that. Most marriages end in divorce after infidelity, as they should. It is legitimate to take the position that she divorced you when she engaged in her affair.
You need to consider this. You're not too young to start over. I have a friend who divorced recently around age 60. My friend, for men of our age, if you're solvent and employed and your junk still works like normal, it's a buyer's market out there for divorced men. In my case, my cheating ex left me for the AP. At the time I was utterly crushed. I felt as if the life and breath were sucked out of both my body and soul. But eventually I picked myself up, dusted myself off, and started putting one foot in front of the other. Let me tell you, my friend: the first time you have sex with somebody new, somebody who wants sex with you just for sex, the feeling is more awesome than words can describe. Like the biggest, coolest drink of water to a man who is almost dead of thirst.
As to the kids, they'll be fine. Millions of kids grow up with divorced parents and live happy, fruitful lives. In fact, modeling a marriage for them like the one you have now, built on white knuckles and resentment, that's doing them a disservice. Do you really want your kids growing up thinking that your current marriage is the model they should strive for?
Also, divorcing before they're out of high school is way better than doing it when they're 18 or 19 or 20 and fledging frm the nest. Over and over we hear from young people whose parents divorce occurs during that period of 18-21, and it's awful, because suddenly they have no home to return to. It's as if they've jumped out of the airplane, but somebody cut their parachute away from them. Do it before they reach that phase, and throw yourself body and soul into being the best shared custody father the world has seen. As teens, they have a lot of say in terms of which parent they stay with. Your "win" in that scenario is that your kids prefer staying with you and do it most of the time.
I wish you luck, my friend.
[This message edited by Butforthegrace at 1:12 PM, Wednesday, August 17th]