I have read quite a bit in the forums here and I am determined to get the DR book when I get home today. I am looking for advice and maybe just some people who listen to me. Here is my story:

My W and I have been married for 17 years. We are both German citizens, but we immigrated to the US before our S8 and D5 were born, so both are US citizens. In fact, the decision to move to this country occurred after our first crisis 11 years ago. I worked abroad for 5 weeks at a time then, and she used the time to have a PA with an OM. Somehow I got her to stay by promising her I would change and probably some of the techniques described here, even though I did not really know about them. When the opportunity came to move to the US, we completely reconciled and decided to move.
Now 11 years later, we end up in a very similar situation. I typically work away from home 4 days a week (Mon thru Thu). We both agreed that I would take this job about 18 months ago. Unfortunately, I also spend some time on my hobbies, and this is where I screwed up badly. She kept complaining about me not spending enough time with the kids, complaining that my family was not a priority for me. I never heard what she was saying.
I do run for an hour or more every morning, but I get up so early that I am sometimes back before she even gets up and the kids go to school or wake - or it does not matter, because I am on the road anyway. In addition, I usually spend an hour on another hobby Thursday (after I get home) or Friday night (if I get home too late), take 1 hour off of work on Friday (as I am working from home and the kids are at school), and another hour one morning (Sat or Sun), but involving the kids. The rest of my 3-day weekend I spend with her and the kids, unless there is a lot of work I still need to do on Friday.

We have had lots of arguments over the last months, but also before, and they always led to the same outcome. If I fought back or I told her that it was not true, it turned into a real fight. She does take care of the household and kids in school, as she is a SAHM, while I occasionally help in the house and take care of all the kids' needs on the weekends. But of course in her mind, I am not doing enough to support her.
Over the last few months, she discovered that our S8 has some problems in school, particularly with reading. She thinks it is a learning disability, while I tried to work on it with my S8. We have had so many arguments about the kids, and she keeps undermining my attempts to discipline them. I kind of gave up, and the result is that kids watch TV all day (when I am not there), my S8 does not do his homework and they do not clean up after themselves. All over the house, there are toys and even trash that she never makes them put or throw away.
She has fought with the school to get an psycho-analytical evaluation, which the school finally agreed to do. We have been discussing this topic for several months every time I call her from the road, and it is the first and almost the only thing we talk about when I get home. She spends hours and hours searching the internet and at the same time, she constantly plays solitaire almost like an addict.
It was driving me nuts. When I told her that I needed a break, she repeated again the kids were not my priority. So I chose to avoid her one Thursday night after getting home. I went about my hobby and watched TV, probably one of my worst mistakes. She has been attacking me ever since that I let her down in this whole mess with the school.
A few weeks ago, I made another fatal mistake. At the end of an argument, she said that either I go to MC with her, or she wants a D. I probably was just surprised by this and walked away without really responding. Now she demands a divorce. However, I may have a little bit of time, even though there are also a few things that make the whole story more complicated.

Two months ago, she had gone to a 25-year high school reunion in Germany, where she apparently met an OM. She does not know yet that I know. I do not believe it became physical in the short period of time (just an extended weekend), but there is for sure an EA. I found e-mails and there are phone calls to a number I do not recognize. Now she revealed that she wants to move back to Germany with the kids next summer.
I was devastated after she told me that. I do not want to lose her, but for sure I do not want to lose my kids. Through my company's EAP, I was able to talk to a L and got some good news. My D5 does not have a valid passport. To renew it, she will need me to show up at the passport office. So she cannot leave abroad with the kids. He also recommended to secure my S8's passport.
In addition, my boss, who is also a good friend, is working on transferring me to a position where I can work from home. I may have to take a pay cut, but that is the least of my worries. I guess I just want to be prepared.

Nevertheless, it is extremely hard to get through the day. I have to function at work, and when I finally get back to my hotel room, I am ready to cry. I keep wondering why every disagreement turned into an argument. When we reconciled 11 years ago, I gave her a bunch of coupons. She would only have to show them to me, and I promised her to listen, to spend time with her, to join her in whatever she wanted to do. She never used them once. Now that I think about it, she never told me how she felt when we had these arguments, it was only you do this and you don’t do that and she recently told me that she expected me to know how she felt. But all I saw was an angry woman who never seemed to be satisfied. She made me angry, too, and so I said a lot of things I should not have said. Now I understand though that if I want her back I need to stop blaming her (even if she is the one to blame) and that I need to start focusing on myself and my behavior. I did not write all this to blame her, but to express how I felt about what was going on. I probably need to start acting as if I am ready to take the blame (I actually did start that by giving her a letter with all my wrongdoings and apologizing for them - it felt like validating what she had been saying over last couple of weeks, months, maybe years).
So as far as saving my marriage, I am going to marriage counseling next Monday, but I am afraid that it will not really help, as long as she does not come with me. I hope to get some emotional relief, but to make a true attempt at saving it, I think I want to try DB. And this is where I will need some feedback.

I am planning to tell her about marriage counseling and to let her know that she can come with me, but that she needs to want it, so it is her decision. I will also let her know that I will be there if she wants to talk, but I will not bother her with how I am dealing with this emotionally. I will be a good father to the kids and a good friend to her.
But I would like your advice on what to do about the EA. I was thinking about telling her that I have a strong suspicion that somebody is waiting for her in Germany, just because I know her (I do not want to tell her that I "investigated" this). She told me that she does understand that it always takes a sledgehammer hitting me before I wake up. I am truly disappointed that she only confronts me and threatens with divorce when there is a safety net for her. Will this alienate her or does this send a message that I am about to GAL?

Looking for help and advice. And thank you for listening!