Brlywtr,
Brother, I know what this is like, I went through this (am still going through it, albeit out the other side!) when I found out about my wife's affair. To add further insult to injury, I found out three weeks after I'd kicked her out that she was actually with a second AP, and that she'd introduced him to my 3 kids. It still does my head in.
Purely as background, in my instance, she had had an affair back in 2013 barely one year into our marriage, and I had erroneously 'thought' that our long and painful reconciliation was a good 9 years behind us in the past, and that she'd learned her lesson. How wrong I was. My priority was the kids. I can tell you mate that my kids have adapted post-D magnificently, and I want you to take some solace in that kids are more resilient and adaptable than you might think. Your job at this point in time is to be the stable rock for your kids; the responsible one whom they can rely on.
First and foremost, your priority should be getting yourself out of infidelity. You wife doesn't get to cake-eat, rock her world with cold indifference and plough on ahead with planning your life like she is no longer part of it. Affairs don't survive in the sunlight, and she will find very quickly that the fantasy life she thinks she is going to lead with this under-achiever is precisely that: a sick fantasy. Second time around, I didn't even try and fight for my wife, I told her to get her crap and move out to a friend's place, and a week later I sent her a ordered and forensically laid-out spreadsheet of our finances including the proposed split. By the time she'd come back around to pick up more things from the house, I'd hung new artwork, moved furniture, and made it abundantly clear that my life was moving on without her. You need to do the same; as much as it hurts, showing your wife you don't need her and WILL move on without her in a place of moral superiority is extremely powerful at this point.
Secondly, I know exactly what it is like to have suicidal thoughts at this time. There was one day at the complete emotional nadir of my situation I scared myself in regards to how close some of those thoughts got. I went to the doctor's and he prescribed some anti-anxiety/anti-depressants to help me through that time. I can not overstate how helpful that was, instead of sitting at a 8 or 9 for stress (and then having something happen would send me to 11-12!), I found I was sitting at a 4-5; so if something triggered me, I would only hit a 8 or 9...which meant I could deal with it. in essence, please see a GP. And a therapist. Having someone to talk to is amazingly helpful as you process this.
In the case you end up pursuing divorce, from a financial POV, a good piece of advice is to tie your wife down to an amicable agreement that benefits you while her head is in the affair clouds. You don't have to go to court, you can reach a legal agreement between you both. Striking early while she's giddy with 'what might be' is often a good tactic.
In regards to dealing with your wife, there is one piece of advice that helped me, and that is that the person you thought your wife was is dead. The person you thought she was never existed. The 'thing' wearing her skin is what your wife truly is, someone who was merely looking for opportunity to betray her husband and family. There is a very poignant quote regarding dealing with infidelity whereby a partner says 'it would have been easier to bury them' in so much that dealing with losing them in an accident or to illness would hurt less than losing them to infidelity - because losing someone to infidelity means that person made multiple decisions on a daily basis to willingly inflict this hurt on you. Deal with your wife appropriately in that regard, she is not an ally, she is at this point your worst enemy and she 100% does not have your interests at heart.
Also mate, in the case that you do go through with divorce (and I know this is all in the future and very far from your mind at the moment) I want you to know that as a single Dad who has just gone through this, I want you to take a great deal of solace that you will have absolutely ZERO problems with meeting someone who will adore you and respect you. Amusingly, at no point in my eventual dips into dating post-separation did I ever meet a woman who turned her nose up at me having kids. In fact, the majority found it endearing, as I would assume those same women came to the conclusion that a responsible single Dad was quite the catch (well, maybe rightly or wrongly, haha!) Your wife will not have the same experience when (and I say WHEN) it all goes pear-shaped with Bob the not-so-financially-independent Builder. It's not fair to women, but we don't make the rules!
In my example, I am now dating an absolutely wonderful woman (who coincidentally is way hotter than my ex, haha!) who adores my children, and who absolutely loathes cheaters having gone through similar. I concentrated all my focus and anger on going to the gym, and packed on muscle accordingly. My oldest daughter told me that 'Mum said she saw you in the car running without a shirt on the other day around the neighbourhood and that we didn't recognise you because you are so buff.' 
As for my ex? Predictably, the first AP cut her away like a bad habit to chase another girlfriend, and second AP has now informed my ex-wife that he is moving overseas in the next two weeks - without her. She is now finding out exactly how much I did around the house, and how much of the finances I used to cover for us. The karma bus collects them at some stage mate, trust me!
I am sorry you are going through this, especially at Christmas. It WILL get better, I promise you. Post as much as you need, we are here to help you through this.
[This message edited by Hurthalo at 11:34 PM, Wednesday, December 20th]
